k_grove wrote:
Found a similar issue for a different machine (disk not ejected properly when time machi… - Apple Community)
The backup itself fails to complete.
Tried what was suggested, but nothing seemed to work.
And no, I did not disconnect my external "Time Machine" hard drive while running the backup. I'm not that much of a rookie
https://discussions.apple.com/content/attachment/de915d68-34dc-448c-9b57-83ba374f97c8
Drive ejecting unexpected ly can indicate a failing drive...
Try a different backup drive and compare your results.
No other drive to compare— then erase, reformat,initialize the drive as new and try your luck
Erase and reformat a storage device in Disk Utility on Mac
https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/22.0/mac/13.0
If you value your user data
3-2-1 Backup Strategy: three copies of your data, two different methods, and one offsite.
More than one device, more than one backup methodology.