Sometimes, if you're running on integrated graphics or playing on a laptop, it'll just do that and be unavoidable. But usually in other circumstances it's the fullscreen bug, which you can check by running the game in windowed. Change Fullscreen=1 in the .ini to equal 0, and add the line AllowWindowedMode=1 under the graphics options. Also disable frame buffer effects for good measure. If that works, it's the fullscreen bug, and you can get around it by either continuing in windowed mode or patching the game to your monitor's resolution with UniWS then upscaling the cutscenes so they match your resolution, which prevents the game from auto-minimizing (there's an admittedly kind of bad but at least exhaustive youtube tutorial for both of these).
I'm doing MY part!
