Location keywords deleted after sync

In LRC, I have many hierarchical keyword structures, amongst which are locations, i.e. Country/State/City and in some cases location or street name.  Since version 15.4.1, LRC deletes upper level location keywords (Country and State, or when there's a fourth level then it deletes the city too) after a photo has been synced to the cloud. The keywords still exist in the cloud. I have checked other hierarchical trees and the keywords are all syncing correctly. If I reenter the locations the save metadata to file, the keywords once again disappear.

I'm running LRC 15.4.1 on a Windows 11 Pro computer with Admin rights. Lightroom, catalog and photos are all on (separate) local nvme ssds. Plenty of space, plenty of speed.