Music app using data when playing downloaded songs

Hi all. So the music app has cellular data turned off and all of my music on my iphone, ios 11.2.6 is physically downloaded onto the phone via itunes syncing and backups setup. I have noticed that when playing my music when not on wifi, again all downloaded onto the phone and the app is not allowed to use data, it will still use data during the use of the app.

This data usage does not show up under the app in Settings-cellular, it shows up under the title “itunes media services” in Settings-Cellular-System Services.

I have the same thing happening with games that do not have access to cellular data, and do not need connection in order to function. When opening not on wifi, they use data under “itunes accounts” in system services.

When listening to music and using the same games on my old ipod, they worked without wifi connection, so why are they using data when they shouldn’t be on the iphone?

The phone i have now is iphone 8, ios11.2.6 and ghis is actually a replacement phone as the first iphone 8 i had, running same ios, was doing the same thing.

Has anyone else been experiencing this?

Thanks!