Unable to join friend on some games but can we both play multiplayer

On certain games I can't join my friend. We both have open NAT types and can join others, it's only eachother we can't join. On some games (BF1, Rainbow Six: Siege, etc...) it's perfectly fine with little to no problem. But on certain games (GTA: Online,
Warframe, and a few others) we can't join at all. This especially prevalent in GTA: Online, where if I try to join him, it will disconnect him from the session and not allow him to join back, if I'm able to join at all. I appreciate any form of help as I really
want to play with my friend

:)

 

Can’t connect to host on xbox one

So i am unable to connect to my friend or my friend to me. When we try to join each other it says unable to connect to host. This has happened in multiple different games. Both of our nat types are set to open. We can only play in the same game if someone
else hosts it. Help us please. I just want to play some cod with my friend!

 

Can't join friend

I'm trying to join my friend in online coop but everytime we get an error, something as "unable to join game".

I've already tried lot of solutions found on internet, change diablo settings, network, but nothing is working.

We have both open nat, and can join together on all other games.

Thank you.