Not sure my reply to your comment was successfully received:

2021-01-21 10:35:25.509 DEBUG 63738 --- [o-8080-Acceptor] o.apache.tomcat.util.threads.LimitLatch  : Counting up[http-nio-8080-Acceptor] latch=1
2021-01-21 10:35:25.510 DEBUG 63738 --- [nio-8080-exec-8] o.a.tomcat.util.net.SocketWrapperBase    : Socket: [org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@36941b88:org.apache.tomcat.util.net.NioChannel@2296b7c5:java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:59275]], Read from buffer: [0]
2021-01-21 10:35:25.510 DEBUG 63738 --- [nio-8080-exec-8] org.apache.tomcat.util.net.NioEndpoint   : Socket: [org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@36941b88:org.apache.tomcat.util.net.NioChannel@2296b7c5:java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:59275]], Read direct from socket: [756]
2021-01-21 10:35:25.510 DEBUG 63738 --- [nio-8080-exec-8] o.a.coyote.http11.Http11InputBuffer      : Received [GET /oauth2/authorization/github?redirect_uri=http://localhost:5000/oauth/jwt HTTP/1.1
accept-language: en-US,en;q=0.9
accept-encoding: gzip, deflate, br
referer: http://localhost:5000/entry/sign-in
sec-fetch-dest: document
sec-fetch-user: ?1
sec-fetch-mode: navigate
sec-fetch-site: same-origin
accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36
upgrade-insecure-requests: 1
sec-ch-ua-mobile: ?0
sec-ch-ua: "Google Chrome";v="87", " Not;A Brand";v="99", "Chromium";v="87"
connection: close
host: 127.0.0.1:8080

]
2021-01-21 10:35:25.510 DEBUG 63738 --- [nio-8080-exec-8] o.a.c.authenticator.AuthenticatorBase    : Security checking request GET /oauth2/authorization/github
2021-01-21 10:35:25.510 DEBUG 63738 --- [nio-8080-exec-8] org.apache.catalina.realm.RealmBase      :   No applicable constraints defined
2021-01-21 10:35:25.510 DEBUG 63738 --- [nio-8080-exec-8] o.a.c.authenticator.AuthenticatorBase    : Not subject to any constraint
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.security.web.FilterChainProxy        : /oauth2/authorization/github?redirect_uri=http://localhost:5000/oauth/jwt at position 1 of 15 in additional filter chain; firing Filter: 'WebAsyncManagerIntegrationFilter'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.security.web.FilterChainProxy        : /oauth2/authorization/github?redirect_uri=http://localhost:5000/oauth/jwt at position 2 of 15 in additional filter chain; firing Filter: 'SecurityContextPersistenceFilter'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.security.web.FilterChainProxy        : /oauth2/authorization/github?redirect_uri=http://localhost:5000/oauth/jwt at position 3 of 15 in additional filter chain; firing Filter: 'HeaderWriterFilter'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.security.web.FilterChainProxy        : /oauth2/authorization/github?redirect_uri=http://localhost:5000/oauth/jwt at position 4 of 15 in additional filter chain; firing Filter: 'LogoutFilter'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', GET]
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.u.matcher.AntPathRequestMatcher  : Checking match of request : '/oauth2/authorization/github'; against '/logout'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', POST]
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.u.matcher.AntPathRequestMatcher  : Request 'GET /oauth2/authorization/github' doesn't match 'POST /logout'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', PUT]
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.u.matcher.AntPathRequestMatcher  : Request 'GET /oauth2/authorization/github' doesn't match 'PUT /logout'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', DELETE]
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.u.matcher.AntPathRequestMatcher  : Request 'GET /oauth2/authorization/github' doesn't match 'DELETE /logout'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.web.util.matcher.OrRequestMatcher  : No matches found
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.security.web.FilterChainProxy        : /oauth2/authorization/github?redirect_uri=http://localhost:5000/oauth/jwt at position 5 of 15 in additional filter chain; firing Filter: 'OAuth2AuthorizationRequestRedirectFilter'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.u.matcher.AntPathRequestMatcher  : Checking match of request : '/oauth2/authorization/github'; against '/oauth2/authorization/{registrationId}'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.u.matcher.AntPathRequestMatcher  : Checking match of request : '/oauth2/authorization/github'; against '/oauth2/authorization/{registrationId}'
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] org.apache.tomcat.util.http.Parameters   : Set encoding to UTF-8
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] org.apache.tomcat.util.http.Parameters   : Decoding query null UTF-8
2021-01-21 10:35:25.511 DEBUG 63738 --- [nio-8080-exec-8] org.apache.tomcat.util.http.Parameters   : Start processing with input [redirect_uri=http://localhost:5000/oauth/jwt]
2021-01-21 10:35:25.513 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.web.DefaultRedirectStrategy        : Redirecting to 'https://github.com/login/oauth/authorize?response_type=code&client_id=c4bf8a5fc184482ec71a&scope=read:user&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D&redirect_uri=http://127.0.0.1:8080/login/oauth2/code/github'
2021-01-21 10:35:25.513 DEBUG 63738 --- [nio-8080-exec-8] o.s.s.w.header.writers.HstsHeaderWriter  : Not injecting HSTS header since it did not match the requestMatcher org.springframework.security.web.header.writers.HstsHeaderWriter$SecureRequestMatcher@41691f80
2021-01-21 10:35:25.513 DEBUG 63738 --- [nio-8080-exec-8] s.s.w.c.SecurityContextPersistenceFilter : SecurityContextHolder now cleared, as request processing completed
2021-01-21 10:35:25.514 DEBUG 63738 --- [nio-8080-exec-8] o.apache.coyote.http11.Http11Processor   : Socket: [org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@36941b88:org.apache.tomcat.util.net.NioChannel@2296b7c5:java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:59275]], Status in: [OPEN_READ], State out: [CLOSED]
2021-01-21 10:35:25.514 DEBUG 63738 --- [nio-8080-exec-8] o.apache.tomcat.util.threads.LimitLatch  : Counting down[http-nio-8080-exec-8] latch=1
2021-01-21 10:35:25.514 DEBUG 63738 --- [nio-8080-exec-8] org.apache.tomcat.util.net.NioEndpoint   : Calling [org.apache.tomcat.util.net.NioEndpoint@131fc5a1].closeSocket([org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@36941b88:org.apache.tomcat.util.net.NioChannel@2296b7c5:java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:59275]])
2021-01-21 10:35:39.169 DEBUG 63738 --- [o-8080-Acceptor] o.apache.tomcat.util.threads.LimitLatch  : Counting up[http-nio-8080-Acceptor] latch=1
2021-01-21 10:35:39.169 DEBUG 63738 --- [o-8080-Acceptor] o.apache.tomcat.util.threads.LimitLatch  : Counting up[http-nio-8080-Acceptor] latch=2
2021-01-21 10:35:39.176 DEBUG 63738 --- [nio-8080-exec-9] o.a.tomcat.util.net.SocketWrapperBase    : Socket: [org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@781b1e42:org.apache.tomcat.util.net.NioChannel@2296b7c5:java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:59279]], Read from buffer: [0]
2021-01-21 10:35:39.176 DEBUG 63738 --- [nio-8080-exec-9] org.apache.tomcat.util.net.NioEndpoint   : Socket: [org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper@781b1e42:org.apache.tomcat.util.net.NioChannel@2296b7c5:java.nio.channels.SocketChannel[connected local=/127.0.0.1:8080 remote=/127.0.0.1:59279]], Read direct from socket: [778]
2021-01-21 10:35:39.176 DEBUG 63738 --- [nio-8080-exec-9] o.a.coyote.http11.Http11InputBuffer      : Received [GET /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D HTTP/1.1
Host: 127.0.0.1:8080
Connection: keep-alive
sec-ch-ua: "Google Chrome";v="87", " Not;A Brand";v="99", "Chromium";v="87"
sec-ch-ua-mobile: ?0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: cross-site
Sec-Fetch-Mode: navigate
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Cookie: JSESSIONID=F6F4EDBF8ADA670C83DA8C7D67EDCB86

]
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.a.t.util.http.Rfc6265CookieProcessor   : Cookies: Parsing b[]: JSESSIONID=F6F4EDBF8ADA670C83DA8C7D67EDCB86
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.a.catalina.connector.CoyoteAdapter     :  Requested cookie session id is F6F4EDBF8ADA670C83DA8C7D67EDCB86
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.a.c.authenticator.AuthenticatorBase    : Security checking request GET /login/oauth2/code/github
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] org.apache.catalina.realm.RealmBase      :   No applicable constraints defined
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.a.c.authenticator.AuthenticatorBase    : Not subject to any constraint
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.s.security.web.FilterChainProxy        : /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D at position 1 of 15 in additional filter chain; firing Filter: 'WebAsyncManagerIntegrationFilter'
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.s.security.web.FilterChainProxy        : /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D at position 2 of 15 in additional filter chain; firing Filter: 'SecurityContextPersistenceFilter'
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.s.security.web.FilterChainProxy        : /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D at position 3 of 15 in additional filter chain; firing Filter: 'HeaderWriterFilter'
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.s.security.web.FilterChainProxy        : /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D at position 4 of 15 in additional filter chain; firing Filter: 'LogoutFilter'
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', GET]
2021-01-21 10:35:39.177 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.w.u.matcher.AntPathRequestMatcher  : Checking match of request : '/login/oauth2/code/github'; against '/logout'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', POST]
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.w.u.matcher.AntPathRequestMatcher  : Request 'GET /login/oauth2/code/github' doesn't match 'POST /logout'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', PUT]
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.w.u.matcher.AntPathRequestMatcher  : Request 'GET /login/oauth2/code/github' doesn't match 'PUT /logout'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.web.util.matcher.OrRequestMatcher  : Trying to match using Ant [pattern='/logout', DELETE]
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.w.u.matcher.AntPathRequestMatcher  : Request 'GET /login/oauth2/code/github' doesn't match 'DELETE /logout'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.web.util.matcher.OrRequestMatcher  : No matches found
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.security.web.FilterChainProxy        : /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D at position 5 of 15 in additional filter chain; firing Filter: 'OAuth2AuthorizationRequestRedirectFilter'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.w.u.matcher.AntPathRequestMatcher  : Checking match of request : '/login/oauth2/code/github'; against '/oauth2/authorization/{registrationId}'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] org.apache.tomcat.util.http.Parameters   : Set encoding to UTF-8
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] org.apache.tomcat.util.http.Parameters   : Decoding query null UTF-8
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] org.apache.tomcat.util.http.Parameters   : Start processing with input [code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D]
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.security.web.FilterChainProxy        : /login/oauth2/code/github?code=ddbf6a23e8136624dd83&state=VoEwkeSdBoLBOaAuYDArErG04mLyVwCCfvoKQgHpu5I%3D at position 6 of 15 in additional filter chain; firing Filter: 'OAuth2LoginAuthenticationFilter'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] o.s.s.w.u.matcher.AntPathRequestMatcher  : Checking match of request : '/login/oauth2/code/github'; against '/login/oauth2/code/*'
2021-01-21 10:35:39.178 DEBUG 63738 --- [nio-8080-exec-9] .s.o.c.w.OAuth2LoginAuthenticationFilter : Request is to process authentication
2021-01-21 10:35:39.179 DEBUG 63738 --- [nio-8080-exec-9] .s.o.c.w.OAuth2LoginAuthenticationFilter : Authentication request failed: org.springframework.security.oauth2.core.OAuth2AuthenticationException: [authorization_request_not_found] 

org.springframework.security.oauth2.core.OAuth2AuthenticationException: [authorization_request_not_found] (coming from filterChain.doFilter(request, response)).

What's weird is what the same code works on another server, for another GitHub user.