Does playing a game through Game Pass for PC mess with buying DLC?

Hello, first it's a pleasure to be able to help you today.

My name is welcome to the community.

Hello Baccaeus, yes this can happen most add-ons, DLC's you have to own the game so you can access it, the add-on needs to recognize the game's contentie, in the case of Game Pass games you do not own the game, just download through the catalog.

Doom Eternal is not a Play Anywhere title so it does not transfer. My guess: You have Game Pass....GP allows you to install the standard edition on PC but not anything else. Same happened to me with Minecraft Dungeons...I own all the DLCs on it but I can only install the standard version through my Game Pass but none of the DLC content.

So, if you want to play the DLC content on PC, you'd need to buy it for PC.

At least that would make the most sense to me.

Yes. If you buy or redeem DLC, you can use it if you're playing the game through Game Pass.

The game pass has an option to buy games through the beta app on PC but it honestly could go either way on whether it would let you play them on PC without the game pass.

The game is available for PC, but not through Microsoft, and it does not work with cross-platform play. So you would have to purchase and play the game on an Xbox One in order to play with your brother.

Whether or not the game will every be made available through Microsoft and Game Pass for PC would be up to the publishers. It is available for Game Pass for the console.