It’s been confirmed that Monster Hunter Wilds has an issue with performance involving DLC, but it’s not what everyone was thinking.
When rumor first spread, there was wild speculation on why the game runs better if you bought DLC. As it turned out, the issue comes from a bug in the game when it checks if you own the DLC or not.
Digital Foundry’s Richard Leadbetter tested the game and verified the issue. Specifically, he claims that the bug will overload your PC with DLC checks, and that’s what’s been hampering performance.
He also tested the “Less DLC Checks” mod, and corroborates that the issue seems to come from the game trying to check for DLC. The modder claims the issue specifically appears when you go to the support desk Felyne that handles your in-game bounties.
Capcom hasn’t shared a statement yet, so PC players are using the mod for now. Hopefully they can address the issue as soon as possible.