[IMMusic]

Add me to the list. I have the same issue. The minor difference is that I attempted to sync to iCloud from macOS (15.5). When that didn't work, I switched over to an iPad running 18.5 and tried it. The same thing happens. It starts and then sits until I cancel it. I’m not sure if this is a clue, but I'm able to sync between the two devices instantly. 

Curt