About 28 days ago, my Facebook account was suddenly terminated out of nowhere. I had no idea what caused it, so I created another account. It was fine for a few weeks, but yesterday that account got terminated too.
As soon as it happened, I submitted an appeal and followed every step carefully. I made sure I had a stable internet connection since you only get one chance to complete the appeal. After waiting a couple of days, BAM, my account was restored.
Later, I found out someone had tried to log into my Facebook account from a different city using Linux. It looks like Facebook's security system flagged the activity and temporarily disabled my account to protect it from being fully compromised.
One thing that seemed to help was checking my Gmail repeatedly until the appeal option became available. I don't know if this will work for everyone, but it might be worth trying if you're in the same situation.
If your account was terminated for no apparent reason, don't lose hope. Submit your appeal carefully, be patient, and keep checking your email. Hopefully this helps someone going through the same thing.
(note that I'm not completely sure if this applies to everyone but I'm giving you ideas or other alternative of what you can do or what might happend to your account)