Android

I'm having a bit of strange problem. I don't have my server on all the time because I only infrequently use it. When I power it off, either by the web ui or poweroff command via ssh, it will occasionally reboot itself. The poweroff appears to work as expected, it will poweroff, the lights will go off, the fans spin down. Then after 2-3 seconds, it powers on again and boots as normal. This is unlike a normal reboot where the fans and lights do not turn off. I've really idea where to begin looking. This has only started in the past few months. I'm running Unraid 6.3.5.