iTunes Media Services is completely out of control draining cell data

I have been encountering this also, with iTunes Media Services eating up my entire data allowance (3 GB) each month since the iOS 17 update despite Apple Music not having mobile data permissions. At the weekend I deleted all offline playlists and in the last 3 days it has ‘only’ used 1.36MB; early days still as to if this is the culprit but worth a try if you’re also having this problem.

Same thing is happening to my wife’s iPhone 12 Mini, beginning in Nov (or Dec?) ‘23. We’ve been getting by with her turning off her cellular data altogether, which is a lame and increasingly impractical solution. And I agree that SravanKra’s rehashed response is not helping to resolve the problem. I have an iPhone 12 Pro purchased at the same time as my wife’s & have gone through the same updates, but so far so good with my phone.

After deleting all your "offline music" did you downloaded your music again? Were you listening to music "offline"? I've had the same problem when I upgraded to iOS 16. An advisor then suggested to turn off completely Background refresh and it worked. The only glitch was that the album illustration were not displayed on my Apple watch, but the crazy iTunes Media Services cellular data draining stopped. When I upgraded to iOS 17 the problem reappeared. I still have this issue only when I am listening to my music outside of Wifi zones. All my music is downloaded, 179 GB in total. All mobile access to music is off. Since then, I have been on the line with 3 senior advisors and 2 Apple store geniuses that unfortunately don't have a solution and are reluctant to escalate this issue to top engineers. I once forgot my Apple watch at home and tested playing music through the headphones. It wasn't draining the cellular data! I reproduced this test with and without the Apple watch and it confirmed that in my case the bug is related to wearing my Apple watch when I'm listening to my downloaded songs. I remembered that when this issue was resolved in iOS 16, my album illustrations on my Watch were gone. Very strange iOS bug! So now I'm still waiting for the last senior advisor to call me back. ...

To turn Cellular Data on or off, go to Settings > Cellular. To set options when Cellular Data is on, go to Settings > Cellular > Cellular Data Options, then do any of the following: Reduce cellular usage: Turn on Low Data Mode, or tap Data Mode, then choose Low Data Mode.

View or change cellular data settings on iPhone - Apple Support

Did you ever find a solution? I'm dealing with this now and neither Apple nor my cell carrier can figure it out.