The other answers are correct but I have not gotten cashapp to work. I use an old phone connected to my current phone via hotspot on the rare occasion I need cashapp.
I still recommend GrapheneOS regardless, almost everything else works with nothing more than minor tweaks. If you want something that “just works”, you’ll run into some hangups. Privacy unfortunately has a cost.
I don’t know the price and since you’re on a .de server I definitely can’t say for sure, but check out the 3M screwplugs. They’re like the foam earplugs you’re used to but they’re easy to put in/take out and they last a while.