1&1/Ionos is one of the largest and best connected ISP and Hosting providers in Germany, not some small shady shop. I see they doubled the price to 2€ though :)
Can't complain about 1&1, also had dedicated 1HE boxes there for a long time w/o issues but I understand the grief in case something goes wrong.
I host DNS elsewhere so I can relocate such a simple proxy within a few minutes, that's what my desaster recovery plan looks like.
Turns out finding a good, reliable hosting provider who isn't a tyrant and gives you the benefit of the doubt & treats you like a human when something's up is really really hard. And probably not very cheap. It's kinda sad that one could host all kinds of interesting things on a $5 device like raspberry pi zero, but then you have to pay out of your nose -- twice, and every month -- to get proper internet access.