(Note, this was also reported here: Connection lost during callback · Issue #28 · soudis/discoursesso · GitHub)
we are having a very weird issue with our Discourse SSO. Ever since one user logged out of impersonation, he is unable to log back in. This is what happens now if he tries to log in: (the user was logged into Nextcloud previously).
The Server just closes the connection. I am unable to find any error log. Not inside any of the nginx proxies, not inside Discourse, not inside Nextcloud.
Interestingly it has nothing to do with the network or device. It is just this user that fails to log in.
I also tried clearing out the SSO Data from Discourse, changed the Email Address to force creation of a new Discourse Account. The Problem still persists.
I suspect this is an issue with the Nextcloud plugin, however I don’t see any error messages by Discourse, which surprises me. (I cleared the log and tried again, no record appeared.)