I am having the same problem, computer will not go to sleep.
I have tried solving this and cant see Ms UsoCoreWorker in the taks manager or in the CMD :
C:\WINDOWS\system32>powercfg /requests
DISPLAY:
None.
SYSTEM:
None.
AWAYMODE:
None.
EXECUTION:
None.
PERFBOOST:
None.
ACTIVELOCKSCREEN:
None.
Computer still will just not sleep, SO frustrating ...
r