That sounds infuriating. I hope you can recover your account.

My initial suspicion was that my account was flagged because I only used the web version (the PWA experience on mobile is pretty good) so I've been using the Android app the last few days, and I'll see if that has any signal on my account.

In another view days I'll try filing a support ticket, maybe claiming something like "I was mass-reported by DSA leftists for my right-wing views"; things along those lines have gotten some peoples' permanent suspensions lifted.