That's not good @Mimi69
Please check that all apps etc are updated so that they are optimised.
Perhaps go into Safe Mode which disables any downloaded apps and leaves the stock ones working and then see what happens. This should help highlight if one or more apps are causing conflicts.
If this was my situation and the above does not help then I'd first clear the phones system cache files.
This is achieved by turning the phone off and then from a set series of button presses go into the phones system files and clear the cache. No personal information is lost this way.
If no joy then as a last resort back up and remove any relevant Sd card and factory reset.
Finally a Samsung Experience Store / Samsung Service Centre can run a diagnostic test.
I wish you all the best with this situation.
Daily Driver > Samsung Galaxy s²³ Ultra 512Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "