Please try the suggestions made by @Charlie . If the issue persists, please send us an error report. We apologize for the inconvenience and appreciate your contribution to the beta program.
One UI Beta Team.
I have the same problem even when tried suggestions made by @Charlie.
I have a note 20 ultra and this problem started when I updated to One UI 3.0 update released a week a go. I think mine is not even Beta. Please help.