[2022] (GeForce NOW 3080 Tier; Un-modded): Missing DLCs/"missing file privileges"

If this were on Windows I'd suspect an antivirus app getting in the way, but even then why would that only affect playing via GFN?

I can only guess this is a GFW issue. Have you contacted them?  

MehmedVII_ said: I am having this problem while trying to play Battlefield 1 in Geforce NOW Turkey. A lot of people besides me have this problem. I reported the problem to support, no response.

That is not a Paradox game so we cannot help you here, sorry. Contact the developer or publisher of that game.