It looks like that a system process is failing. The best way to solve that problem is to back up your data (photos, ecc..)
then power off the device and press volume up (bixby key too if you have then) the press the power button keeping all the above pressed and you will boot into recovery mode. From there do a hard reset which will wipe all your data ect.. you will have to re set up your phone and import all the data that you backed up but you will solve
