Unable to read apfs key lock ranges: No such process checking the object map

I've a the same problem in two HD LaCie 6tb & 8tb
they run first tm ok but then hang on the second.
when i test with disk utility they report the same error.
Running into this issue on my iMac's Apple Fusion drive.

No answers? Apple?
I have the same problem with a external SSD.
Unable to read apfs key lock ranges: No such process checking the object map
 
 
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