itunes purchases not able for download

Downloading previous purchases in itunes. They download fine on my PC, i-phone 6 and my old 2nd generation ipad (now limping along). They will not download onto my new 8th generation ipad, 20% do, 80% roughly $1,000 worth of songs - nope.

I can play them on WiFi but where I live and work WiFi is unavailable in many places. I bought the songs, they are in the iCloud, they are on the old ipad, etc.

They won't sync up either.

Very frustrated.