Xbox Unable to join group due to Xbox live unavailable.

Console bug # 866,927,051.

When attempting to join other players in game. The joining group will load and then not able to join group. And then receive cannot join group because Xbox live is temporarily unavailable. Now I've check Xbox live status and showing that Xbox live is up and running fine. So did reset console and friend reset there console Also. Still not able to join each other?

Also on gateway is on auto.

Also did contact Xbox support they advise to reset Xbox and reset wifi network or contact ur internet provider. Did all steps already.

Yeah, there is something weird going on. Are you on Starlink by any chance? Are you attempting to join a specific friend or just groups in general?

Here's my experience with it: i am able to join pretty much anyone besides one guy on Starlink (US i think?). I was looking out for challenge stuff he needs. Same sequence than the one you are describing.
Here is the funny thing tho which might help you out if you are trying to play with a specific friend - if he joins an existing party from someone else, he is able to invite me from of it. We did a Harvest boss together, no problem.
(Frankfurt/XBSX/Fiber here)

Edit: We tried switching servers of course.

This continues to be a thing, just spoke with someone else who has trouble wth this. He told me he is not on Starlink, as i mentioned my friend (with whom i cannot party up the whole league) had the suspicion it might has to do with it.

Some more info, doubt it helps you guys, but at least gotta try.
The following situation: we wanted to run a Flawless Breachstone. 4 guys. My mentioned friend parties up with Player1, then invites me... this way it works for us, as mentioned in my first post in this thread. Then i invite Player2 who also wants to join - this lead to me leaving the original 3 man group and joining a new one with him. Tried two times, same outcome. I DON'T have Xbox Gold atm btw, which should not be a problem, but maybe there is some old relict in your domestic or MS code that is problematic in this regard? Please contact me if there is more info i could provide that might helps tracking this.

While i never had the impression i was the common denominator in this lol... this is happenign all over this league for me for some reason? Frankfurt server.
Third trade now i got msg'ed via trade side where i had to steer them to the tb, because we were not able to group up.

Just a quick update here, ima just bump this, because i know from chat this has been a frequent problem for a few people...

... i deactivated what's called a "Teredo Filter" in my Fritzbox router. It must have been there in Sanctum aswell, idk, maybe they changed somethign domestically, the router people that is, because i had no probs there.