I saw a similar post and Support made three suggestions: Check network, Reset iPad, and Log out and back in to iCloud. I tried all three. Nothing has changed. My iMac and iPhone have full iTunes sync while the iPad has a very incomplete sync.
iPad Air 2 Wi-Fi, Cellular
On your iPhone, iPad, or iPod touch:
On your iPhone, iPad, or iPod touch:
Btw there’s a new setting now in iOS 13 to reduce data usage
Use Low Data Mode on iPhone, iPad, and iPod touch
https://support.apple.com/en-us/HT210596
“Turn on Low Data Mode in iOS 13 to restrict background network use and save cellular and Wi-Fi usage.
You might want to use Low Data Mode if your cellular or internet plan limits your data usage, or if you're in an area with slow data speeds”
That did the trick. I'd changed the setting long ago when I had limited bandwidh.
iPad Music fails to fully sync with iCloud
