Same. I have 10 years old account. Practically never use it. About a six months ago, I start using it from Miranda. It works fine. One day, I confirmed new friend request through miranda. Next day Facebook kick me out. I reset my password and though, OK, no operations other than messaging trough Miranda. But I was using it about a month and today, I was kicked again - Temporally disabled account. "We’ve detected suspicious activity on your Facebook account and have temporarily locked it as a security precaution."
Important to say - I'm not using a Facebook outside of Miranda at all (not even for logins). No phone apps, no browser on desktop, nothing. I just using it as a messaging platform through miranda ng (on a desktop with permanent location). It is clearly something fishy there and Facebook did not want this type of users. Cant just Miranda NG connect with fake Browser User Agent of Chrome or Firefox? And act as a browser so Facebook did not know it is a 3th party message client? I suspect problem lies there.