Issues With Joining Friends

Ok, so I stopped playing for almost 2 months. I come back to Halo and now I cant join any of my friends.
I keep getting messages saying:
JOINING FAILED
This user can’t be joined as their session is now closed.
it happens with all my friends.
it was working perfectly before.
It’s saying the issues are on MY end.
Why did this start happening?
My ports are not changed.
They are still the same.
Even my 360 says OPEN WHEN I PLUGGED IT IN.
it is no longer hooked up.
I have not had a good experience with matchmaking at all.
I continue helplessly to join and join wasting hours away trying to figure out a solution.

I beg please help, I want to play the game with my friends.
I truly enjoy Halo, always have.
I just feel like I’m at the end and I have not yet sold my Xbox cause I like Halo that much.

same issue

Have you tried power cycling your console? I had the same issue, and that fixed mine. Also be sure your firmware on your router and modem are up to date. Firmware can cause connection meshing issues, but that’s from my experience. Hope it helps.