I have the same issue. I never had issues activating my account and don’t have 2FA turned on yet, but no matter what I do, it will not save any changes I make to my preferences.

Even today, tried to update my profile pic, uploaded, saved, everything, and poof, nothing.

AND - I’ve tried it on 2 different computers on Chrome and on Safari on desktop (that I never use), and on mobile Safari. Nothing sticks on any device or browser.