Mine has done the same thing a few times. I started keeping the fob in a hard shell pouch designed for keeping earbuds in. That way I can’t accidentally push the buttons on it. I haven’t had it starting unexpectedly nor have I had doors opening when I don’t expect them to.
I wasn’t pushing the buttons though. It was happening during the night while everyone was asleep. (Unless a mouse ran across the key fob or something-)