Don't worry about that now, let's just get to the bottom of the issue. Once we've sorted it we can look at rooting if you really want to..... Google music was part of the last update you had so it's classed as a system app.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)