Solution: the RPM Fedora version did work, the version from Flathub or the Fedora flatpack repo did not work. I guess the flatpack versions don't have the most recent xfreerdp version? I don't really know...
You should put your pihole server in the dns server in the network settings. My mobile devices didn't use my pihole server until I changed the dns server configured there... (I am using a FritzBox as well)
Sorry folks was too busy today, maybe I'll get to it tomorrow, but I don't know. Might take til saturday for me to try your suggestions, but I am very thankful for every reply I got
Well google doesn't have realtime results. They obviously still have your account on there, because they crawled it propable ages ago... When you click the link though, reddit tells you that this account doesn't exist, so no BS. Just how such things work