Time machine will not complete first backup
I have been using the same G-drive Pro Enterprises Desktop 6Tb for all TimeMachine backups. As of Oct 23, TimeMachine has decided that it could no longer back up to it. The drive is not full. I've first aided, erased and reformatted it. It was APFS then and still is now. The only message I receive is that "Time Machine couldn’t complete the backup to “G-Drive (Time Machine). An error occurred while preparing the backup.”
There is no other options. I'm out of ideas. This drive is brand new (purchased thrtee ago Oct 2022). What's going on?
Mac OS Monterey v12.6
iMac Pro