Time machine HD keeps pounding and spinning all the time
Mac Pro 3.5GHz 6-core, 64GB RAM, AMD D500 3GB GPU, 1TB internal SSD.
MacOS Monterey, Version 12.6.5
External USB Seagate 10TB Drive for Time machine. Single partition
When the HD is mounted, it just constantly is hammering away... clickity clickity clickity as if it's being written to, but time machine isn't busy with a backup. It will go on forever. I can't figure out what it's doing. How do figure this out. It has no business being hammered on like that. Normally it should be sitting quietly doing nothing.
I ran a diagnostics and it says it's OK. As soon as I mount the disk is starts hammering away again.
thanks
Mac Pro, OS X 10.11