Hi,
it's 99% a logical issue, where something in your components or fsm that disable that gameobject. It could be one of the component you use from Unity or third party and not necessarly from one of your fsm.
try to isolate your player in a new scene and see if you get that again, if yes, make a copy, try again, and cut down features until it stops, which will mean it's the last feature you removed that was the problem.
Bye,
Jean