That sounds like an issue specific to the GFN servers in your region rather than the game itself. Sometimes certain free-to-play titles don’t handshake properly with Steam through GeForce NOW if the regional server has a misconfiguration.

A couple things you can try:
– Make sure your Steam account is properly linked inside GFN and you’ve launched the game at least once locally on your PC (sometimes this “activates” the entitlement).
– Test with a different GFN region (if you have access to switch servers) to see if it’s only UK Area 2.
– Check the official GFN status page or NVIDIA forums — connection errors for specific titles are often listed as known issues.

If it works in another region but not UK Area 2, then it’s almost certainly a GFN server-side issue, and the only solution is to report it via NVIDIA Support so they can fix it on their end.