Multi GPU multi monitoor video hardware acceleration

Im using KDE 6 with wayland. Garuda Linux / Arch based. My setup got an nvidia gpu 555 beta drivers. Also an intel-igpu. 2 physical screens connected to the intel i-gpu and the gaming screen is connected to the nvidia gpu. All three dispalys work. But apparently the nvidia card does all the work. Lets say i put a video on one of the displays connected to the intel i-gpu. I would expect the intel i-gpu to do the video decoding / hardware acceleration. But in fact the nvidia card does. Any clues about this behavior?