Forced restart doesn’t work

Force restart iPad - Apple Support

You should try the forced restart process again. It usually takes a couple of attempts to get the speed and sequence of pushing the buttons correctly for the restart to occur. The last step of holding the side button until the Apple logo appears could take up to 30 seconds. If after holding the side button in the last step for 30 seconds doesn't restart automatically and the screen shows Slide to Power off, then the speed or sequence was not correct.

if it was me then I would

try restarting the ios device Force restart iPhone - Apple Support and check if it resolved it

if it did not

then I would try Restore your iPhone, iPad, or iPod to factory settings - Apple Support -

f that did not resolve it then I would

contact apple about repair Contact - Official Apple Support