Trouble Restore Big Sur from Time Machine Backup

I talked with Apple Help Desk and because Big Sur is still in beta, they couldn’t offer much help. I haven’t had many problems with Big Sur since downloading weeks ago. I made a backup of Catalina before I moved over to Big Sur. Yesterday Sept 8, I had to go back to Catalina to use software to take an online test. Backed up Big Sur using Time Machine. Used Time Machine to start Catalina back up. No problem. I passed the big test (yay!). Went to restore from Big Sur last night into today Sept 9, from the a Time Machine backup found on my external hard drive:
I get this loop: 

Restore from Time Machine
Seagate Desktop Drive
September 8, 2020 1:13:27 PM PDT MacOS Version: 20A5354i
‘You must use Migration Assistant to transfer data from this backup. Reinstall macOS if necessary and then use Migration Assistant to transfer data from your backup”
macOS Big Sur Beta
Install it on Disk (although it’s already on the disk)
It downloads it (again), and boots up Big Sur (even though it’s already installed on the disk)
Problem is it doesn’t back up at all from yesterday’s restore point. Confounding
Rinse and repeat. I’ve done this three times so far. 

Ideally I’d love to pick up from where I left off yesterday, but if I could just have the files I accumulated the last several weeks, that would fine.
The tech I talked to said that Big Sur should be ready for prime time soon, but couldn’t guarantee me support because it was in beta. So she recommend post here. Thanks in advance! - Shawn
Trouble Restore Big Sur from Time Machine Backup
 
 
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