Okay, I'll start with a short yap and say thank you very much and from here I'll try to cut it short.
Problem: I get kicked out of games unwillingly and without and sorts of warning. I can only re-join the game when my Xbox picks up the connections again.
Situation: I'm wired per LAN cable but I have tried WLAN as well, both didn't work. I am using the same router as always and the Xbox has been working just fine ever since I bought it. It only started doing this about 2 months ago.
Proof internet isn't at fault: I have a Series S next to it where my gf plays and she's gaming perfectly fine. As well as my smartphone laptop or other's are complaining. It's only my Xbox Series X with this problem.
Internet specs tested by the Xbox build in feature: about 260mbs download, 30mbs upload, 23 ping, 0% packetloss.
I have tried on the xbox: rebooting the Xbox, hard resetting the Xbox, 100% factory reset the Xbox, set an alternative port on the Xbox
I have tried on the router (Fritz.Box9960): restart router, factory reset router, turn off toredo filter, give Xbox Internet priority, set ALL ports the Xbox could possibly use stated by Microsoft official NAT help post, give Xbox privilege to set ports on itself
I think I'm literally just doomed am I? I don't want to believe that this could be a hardware caused issue. Again, thank you so much for your help! I need to get this to work before sparking zero 😟🙏🏻