First try putting the phone in Safe Mode which disables any downloaded apps and leaves the stock ones working and then see what happens.
Check there are no software updates in your phones settings.
If it continues then if this was my situation I'd back up and factory reset.
If it continues still then seek support from a Samsung Experience Store / Samsung Service Centre
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I have no affiliation with Samsung.
I also have the same problem: it started 12th of July 2020.
I might have an hardware issue, as it does not turn on unless I connect a charger to it for 1 minute, then disconnect the charger, waith another minute and then the phone starts.