I noticed that if I check "Stay logged in", then it'll work just fine.
As a test, I tried it here on the xF site and things work as they should.
I then disabled all mods I have installed thinking it was one of those. But the same problem is happening.
I cleaned the cache of MS Edge, F5'd the page, etc. Nothing seems to make the login work without the "Say Logged In" checked.
Thanks for any help anyone can provide!