Did you buy the phone new from a reputable supplier, or second hand from somewhere else?
Have you had the phone long?
Maybe worth clearing the Partition Cache of the phone.
Should be straightforward
https://www.t-mobile.com/support/devices/android/samsung-galaxy-s20-5g/wipe-cache-partition-samsung-...Have you tried backing up your data and doing a factory reset?
Going to a Samsung Experience Store could be a good idea, as they will be able to tell you what has happened, or fix the issue.
If all else fails then if you only recently got the phone, maybe worth going back to the supplier