Bizarre OS behavior after Catalina Upgrade and Time Machine backup error

[MareLuce]

Am now seeing a bizarre behavior in my always reliable, problem-free (even the keyboard), recently upgraded to Catalina, 3 year old, 2TB MBP.

When I copy a file anywhere, it asks me to authenticate via Touch ID or my Admin password.
However:
- Touch ID does not recognize my fingerprint.
- My watch makes the haptic sound but that does not work.

I must enter my admin / user password for every file copy action.
I want to reboot but I’m panic’d about my formerly reliable system being worse when I reboot.

So I’m copying off my critical data to an external drive first.
No Time Machine, Not Carbon Copy Cloner. Just a straight file copy.

Any ideas?

This behavior started after my Time Machine backup to Synology ended with
"Time Machine could not complete the backup to: [ synology URL ]
Error code: 640"

The only other thing I've done recently is tried to use this laptop as a source for Migration Assistant to a new 16" which I've since returned.

2 links I’ve found related to Time Machine Error code: 640

https://discussions.apple.com/thread/250833440

http://fixmacissue.com/fix-error-code-640-on-mac.html

 

[MareLuce]

fyi - taking a hot shower and rebooting from a cold laptop seems to have fixed the above

so odd...