Power outage triggers motion detected

I have one motion detector in a room in the basement that has access to the outside. We were away from home one day and got a notification that ring was working on battery because we lost power and the next thing, my alarm is going off because there was motion detected. I feared someone cut power to my house and broke in or a tree fell into the basement door, but luckily it was neither and we had just lost power. We lost power again a few months later, the alarm was not set at the time, but I did notice there was motion detected at the same time as the power outage. No one went in this area at the time and shouldn't have triggered motion. We haven't used the motion detector since then, but lost power again yesterday and once again motion detected. Why does this keep happening? I can't use my motion detector for fear of triggering a false alarm, especially when I'm away from home or sleeping. Anyone else have this problem?