time machine disk not ejected properly
New Mac Studio two days ago. M2. I'm using Time Machine to backup to a USB connected drive. Everything is working well but when I sit down to the computer to resume working I always get a 'time machine disk not ejected properly' warning for the Time Machine drive. I DO have Put Hard Disks to sleep when possible turned OFF. The drive is still 'connected' in Focus and Disk Utility and continues to back up hourly. I can look at the drive and see the Time Machine backups instact. It's just the annoying message that's driving me crazy.
Suggestions? I found similar posts but nobody seems to have a fix. Apple support only tells me to replace the drive. I have 4 external drives and they all have the same issue. The drive I'm using worked fine on my 2017 iMac 27 inch without this issue.
It might be a M2 issue?
Thanks in advance. Don
Mac Studio (2022)