After more digging, it seems that these video I'm working with indeed has a naturalSize of (4.0, 3.0). When opened in QuickTime, when you bring the Inspector, it says they are display at Current Scale of 272x or so, while a regular video I tool from internet is displayed at 0.62x for example if that's a HD video. Anybody knows : what metadata that information is and how to deal with it? Why it is different on the original track than when put on a different composition? How I can extract a frame on such videos?

Did a complete writeup here with Playground https://stackoverflow.com/questions/66597674/my-videos-have-a-naturalsize-of-only-4-0-3-0-pixels-which-is-also-extracted

Did you ever find a workaround or a solution to this ? Having the same issue on macOS. I want to doubleTap() a thumbnail, but a single tap is recognized and selects the item instead of opening it.