Just fyi, I believe T-Mobile is one of the main networks that Fi uses. So it’s still possibly network related.

Algorithms don’t have “inspiration”.

I’m not sure what country you’re in, but have you tried Amazon? I found Verbatim 50 packs of 25GB for $40 and Ridata (usually good quality discs) for $28. If you want small amounts there’s various 5 packs for less than $10.

Mine does that too. It’s actually all done on device with a special chip and it periodically updates a database on the phone with digital fingerprints for songs. You’ll notice sometimes it’s just wrong or thinks fan noises are music playing.