Yes, I’ve uploaded the video I want to my content folder, yes I’ve created a media player which plays that video, yes I’ve applied the texture to the material and yes I’ve put it in the sequencer. I set the media source binding ID to the camera I want viewing the texture on the media track in the sequencer, I set the media texture to the texture I want viewed on the media track in the properties section, I exported the video in the same resolution as the render in my project, I set pre-roll frames and yes, I made sure the frame range is in the desired set of frames.
media track binding is backwards from what most people expect. the media track does not go on the camera, it goes on the plane actor that shows the video. camera just looks at it.
working order: video file under Content/Movies, File Media Source pointing at it, Media Player asset, Media Texture from that player, then a material (Unlit, Emissive Color wired to the media texture sample) on a plane. in sequencer add that plane actor, add a Media Track to it, set the media source and the media texture there, set preroll frames (8-16) and make the section range cover your shot plus handles. dont skip the preroll, without it the first frames decode late and it looks like the binding is broken when its just late.
this plates and matte painting walkthrough covers both the reference plane setup and the camera-projected material version, plus how to keep it frame accurate out of MRQ with temporal samples: Plates and Matte Paintings in Unreal Engine