Lightroom 14.0.1 Mac M1 Pro it takes hours to move a few photographs

Since the Sync rewrite, performance has been bad.  Since 14.0.1, it has gotten catastrophic.

Last night, I tried to move 3000 photos from a folder into a different folder.  14 hours later, about 10% has finished.  It took over 5 minutes to cancel the move.  Sync is paused.  64G of RAM, 8T of SSD, plenty of free space.  Clean boot and clean restart of LrC last night.

Previously, editing photos was sluggish, and often if I move to view a different photo and then came back to one that I had edited, all the edits would have reverted, and the history would be blank - until, apparently, the edit history had round-tripped through the cloud, which might take 5-10 minutes on a good day.

This is now unusable for me.