[URGENT] Why can't I play mhfu over lan

[Erihs]

Hi there, I have two computers with ppsspp, one on ubuntu, the other on windows 10.
When we launch a quest on mhfu, we can see both of us for something like idk, 5 seconds, and then, on each other screen we see "xxxxxxx broke off from the group"
Within the 5 secondes, we can see each other move and fight, and then nothing else.
Help us please, i'm trying to learn to my little brother the art of hunting!