in my experience that usually boils down to the Linux version getting (an understandably) low priority compared to the windows version. Which is something that won’t change until Linux has a significant market share and I can’t fault the devs for it. For an example of a game where that is not the case I’d like to take Factorio, where the devs went out of their way to properly work on the Linux native version and even include Linux/Mac exclusive features for their next update. But that only happened because one of the devs themselves uses Linux.
don’t forget the additional ssl cert for the second domain (assuming it’s not a wldcardable subdomain)