https://bugs.winehq.org/show_bug.cgi?id=57406
--- Comment #1 from Esme Povirk madewokherd@gmail.com --- Tried the steam version in Proton. It loads native Microsoft.DirectX.dll and Microsoft.DirectX.DirectInput.dll.
Not sure how you ended up with builtin, but this is a monoDX bug regardless and I should still be able to reproduce it by overriding.