Apparently it was a little problem for me but to be honest it happened to me after unlocking the bootloader and wanting to install a custom rom.
I could not install any return to the normal version of xiomi
and everything is normal until one day I restart it, I felt it very slow and it did not turn on like 20 min and one day I turned it off and it did not turn on what I did was remove the battery for 20 min and download the same OTA THAT I HAD FLSHED WITH THE XIAOMI TOOL AND THE PROBLEM WAS SOLVED
YOU SHUULD TRY