I came across an Android phone which has a very strange phenomenon: it restores to certain status every time it boots or reboots.
Installed apps and saved files will disappear, and uninstalled apps and deleted files will come back after (re)booting.
I tried factory reset from settings and recovery, but neither worked.
It seems the phone is still, and no changes can be done to it.
I'm curious about how it became like this, and wonder if there is a way to solve it.