iCloud Drive upload stuck

A few months ago I migrated to a new laptop. Since then, iCloud Drive is stuck on a few remaining MB's. See screenshot.

Any ideas why and where it is stuck?

I have, of course, rebooted several times, and upgraded to Sonoma 14.5.

Maybe a related problem is that , since then, several folders bear the iCloud "unsynchronized" symbol; and it is exactly those folders that contain aliases or symbolic links.

But maybe this is a separate problem.

Thanks a lot in advance for any hints!