Can’t Join Friend’s Game on Grounded via GeForce NOW (JoinPlatformSession: Failed: 2)

[wasja]

Hello,
I’m trying to play Grounded with my friend through GeForce NOW, but I keep getting the following error message when joining their game:

Error: JoinPlatformSession: Failed: 2 "The game you are trying to join no longer exists."

Things I’ve tried so far:

• Restarted GeForce NOW and the game.

• Made sure I’m signed in to Xbox Live inside the game.

• Asked my friend to re-invite me several times.

• Tried joining both via invite and from the friends list.

Additional info:

• Another player is able to join the same host without issues.

• Up until recently, the game worked perfectly for me.

• On my regular laptop (without GeForce NOW), I can join without problems — but the laptop is too weak to run the game smoothly.

• Other players can also join my hosted games on GeForce NOW without any problems.

So the issue seems to happen only when I try to join someone else’s game through GeForce NOW.

My setup:

• Platform: GeForce NOW (Steam version of Grounded)

• Xbox Live account is linked and active

• Error happens every time I try to join

Could this be related to GeForce NOW cloud sessions, or is there another fix?
Any help would be greatly appreciated!

Thanks in advance.