R8000P reset itself to factory settings by itself with no warning or intervention

My R8000P reset itself to factory defaults last night for absolutely no reason.  I had auto firmware updates off.

I've run this router for a year, had many custom configuration and rules, and for the life of me cannot find the backup.

The fact this thing reset itself with no intervention is absolutely infuriating, moreso in this day and age where one's entire house, lights, cameras, TVs and everything else requires internet to work.

I thought my Internet had gone out due to storm, and through my phone app I hit "reboot" button and that was it.  It came back into factory default settings.

Also its connected to UPS.  No electrical events happened last night, even with the storm.  I just was expecting something like that but everything else stayed working.   Of course now after factory reset half of my house's devices are not working. and I have to spend the next day configuring everything again, and don't even remember it all.

How can that happen?