[Q]Riptide GP2, Play Games and Invitations

I'm having a somewhat weird behavior with my phone.

I'm trying to play Riptide GP2 with a few friends. They can play normally between each other, but I can't. I just don't receive any invitations, when I send one, and people accept them, I don't get the info that they accepted. Of course, I am connected to the internet, I don't have any apps that could block my internet, I made the login perfectly with both the game and the Play Games app, but it doesn't appear on All My Games list...

We are downloading another game to try, but it doesn't make sense whatsoever that Riptide GP2 doesn't work...

Any possible solutions?