I went to Canada a couple weeks before the ban. I also did a new phone. I am linked to Facebook. I think I would know if my account was hacked??
If all this was in a short span I could see it flagging a company with a set algorithm. It's probably how it looks.
Just a brief example...
Let's say you are on Android, Facebook linked in Ohio. Travel to Canada, back to Ohio, new iPhone, unlinked Facebook, linked to a new iPhone and playing again in Ohio. Every company is different but 1-2-3 things might flag an account. It's a combined thing I imagined.