Issues playing publics with my son

[spite]

Hi, my son started to play STW this Christmas and, when we play in private or friends, there’s no problem. But in public ones, can’t join same mission, always one is pushed out, no matter if he tries to join after start mission.
I’m on PC, he is on Xbox. Both wired, different ip’s and upnp on.
Any idea or help to fix it? https://100001.onl/ https://1921681254.mx/
Edited by TembaBavuma, 09 January 2022 - 09:37 AM.