Power Problems

so, i've been using my Rexing M1 for a little while and it has been perfect, however recently there has been some issues, when i power down my car, the camera immediatly shuts down, and the last segment of video it was recording is not saved, the camera is plugged in with the car adapter so its always receiving power, i tried turning it on without being plugged in and it worked, it turned on without a problem, so im kinda stuck with what might be the issue here, since i have to manually stop the recording each time before i turn off my car

thanks