I've had this issue where I can no longer play this game on my phone wether I use the geforce now app or through the browser. I use an android phone (Samsung Galaxy S20 FE). It doesn't matter if I have full 5G or using wifi at home. The game will work when I play on pc with geforce now.
I play in NY and the nearest server is in NJ (set to auto). If I play any other game from my library. It starts up and works just fine. I've logged out and logged back in. Even reinstalled the gfn app.
I was able to play at launch, and it's been about 2 weeks since the game has been unplayable on my phone.