Need help here.

Local files on iPhone disappeared after a couple hours of listening then will not sync again even after relog and reinstall on my Windows desktop, MacBook, and iPhone.

All firewalls disabled. all connected to same wifi network.

The phone and the computers see eachother, they can play other songs perfectly fine, but on the iPhone the local songs are grayed out and when I tap it it says "song not downloaded"

All running latest version of Spotify.

About 6 months ago my local files suddenly disappeared on my phone, so I resynced them. but after a few weeks they disappeared again, so resync. few DAYS later, disappears again. then is became a few hours. and now it wont even sync at all.