I can work around the issue, but what causes it?
I’m not sure.
Has this happened recently?
If possible, can you try and see if you can reproduce the issue using another browser? That way we could better determine whether it’s a browser specific issue or not.
I wrote down a couple things which I think could be causing the problem, but I should mention, I have very limited knowledge when it comes to the lower level stuff for the web, so I’m probably completely wrong on most/all of this.
Do you have any antivirus plugins installed on your web browser? It could be the antivirus plugin logs you out when you try to view your profile. It may be that the antivirus program thinks the forums are a virus for some reason, and so it’s blocking the login information.
If you have a antivirus plugin installed, I would temporarily add the forums as an exception (so it’s not blocking anything on the forums) and see if that fixes the problem.
Another thing that could be causing the issue is how your browser is dealing with web cookies. Because the web cookies are storing whether you are logged in or not, it may be that your browser is not sending the web cookies to the profile page, which makes it think you are signed out.
I’m not sure how to go about checking/fixing this problem, but one thing you could try is logging in while looking at your profile. In theory this would generate new cookies specific to your profile page, which then should allow you to view your profile while logged in.
Hopefully that helps. Later I’ll log in using Microsoft Edge and see if I can reproduce the issue, as it may be that a recent Microsoft Edge update has changed something and is causing the issue.
