Thank you! FYI the claim link says “already claimed” but I was still able to get it from the other link.

You can never have too much cheese!

My bad. I’m on steam deck and have that option.

On the dayz game page where you would click play, click the settings cog on the right. Choose developer, then delete proton files.

I didn’t see this mentioned yet in the comments - have you tried going to developer settings and deleting proton files for the game?