I am also having the same Problem after updating to Big Sur. I was advised by Apple support to reformat my device. After reading the details here not sure whether that would solve my problem or not. Hopefully Apple solves this soon. Frustrated.
KFDOCTOR
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution