The same problem.

java.util.concurrent.CompletionException: java.util.concurrent.CompletionException: com.faforever.client.login.LoginFailedException: Lost connection to server during login
at com.faforever.client.user.UserService.lambda$loginToLobbyServer$11(UserService.java:124)
at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:930)
at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:907)
at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1769)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
at java.base/java.lang.Thread.run(Thread.java:832)
Caused by: java.util.concurrent.CompletionException: com.faforever.client.login.LoginFailedException: Lost connection to server during login
at org.springframework.aop.interceptor.AsyncExecutionAspectSupport.lambda$doSubmit$3(AsyncExecutionAspectSupport.java:279)
at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764)
... 3 more
Caused by: com.faforever.client.login.LoginFailedException: Lost connection to server during login
at com.faforever.client.remote.FafServerAccessorImpl$1.call(FafServerAccessorImpl.java:246)
at com.faforever.client.remote.FafServerAccessorImpl$1.call(FafServerAccessorImpl.java:213)
at javafx.concurrent.Task$TaskCallable.call(Task.java:1425)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at javafx.concurrent.Service.lambda$executeTask$6(Service.java:725)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at javafx.concurrent.Service.lambda$executeTask$7(Service.java:724)
... 3 more