How to create a video for a map?

but the point is that if they are inside the map after the editor is closed, then it's unlikely that anything will happen to them =)

They keep disappearing. The editor loads them in a strange way and doesn't care whether they are there or not. That is, they don't disappear from the map itself, but access to them through the editor's interface becomes difficult, and I haven't been able to identify a pattern. I'm just working with a video, and for example, three times everything is fine, but on the fourth time, I have to do some tricks. Only StartScene saves me ;)

RedHeavenHero - I definitely had this happen a couple of times, where the video is on the map, but it's not visible in the editor.

Yeah, that's exactly it.