Good afternoon, there has been a problem with Windows 11 recently. When playing videos, they become very dark. There is no such problem in screenshots or screen recordings.
This issue might be due to the HDR settings in Windows 11. Try turning off HDR by going to Settings > System > S. Also, check the video playback settings under settings > Apps > Video Playback and turn off "Automatically process video to enhance it." Updating your display drivers might also help. Hope this resolves it!