I had this happen before and didn't think much about it, but it's quite annoying..
I ran Baldur's Gate 3 by copying the installed folder from my windows PC to my steam deck and selecting "import game" when installing in heroic launcher.
The Larian Launcher says "file mismatch" when it starts up, but it tells me some directX files differ, which is to be expected. The game runs perfectly.. Until I update it through heroic launcher.
Then the game starts, but every piece of text in the menu is replaced by "not found", as in the attached image.
I then have to copy the updated game over from my pc, and it works, but copying 120gb every time there's an update is quite annoying.
Any way to diagnose what's going wrong here, or to fix it?