Party and Game Invites Not Working?

I recently switched over to an Xbox Series S from PS4 so that my best friend and I could play video games together from such a far distance. However, after attempting to invite me to a party several times, none of his invites ever got to me and none of
my invites to him never got to him.

Similarly, any game invites we tried did not go through either, what is even weirder is that in-game chat in Halo did not even work.

He is currently on an Xbox One S and when I first got my Series S, he was on do not disturb, when he turned it off it still said it was on and now half the time it says he is on do not disturb and we're not sure if that's the culprit in this situation.

We've tried everything in the book, checking every setting 3 times over, we tried power cycles on both ends, and I even tried digging into my home router for Teredo settings (although I'm pretty sure that was only if you can't hear someone in a party).

I have read some forums hat suggest notifications randomly stop working and then start again, but any help would be huge, we've been waiting such a long time for this and it feels like a big let down right now that I just paid all that money to switch consoles
just so we couldn't talk or even play a game.

Any help is appreciated, thank you all!

:)