The fix that worked for me? Add to your camera camera component the track property; “Auto Activate”.
STEPS:
I just had this issue of the camera pointing at nothing. Tried a few things.
I had a very simple sequence, so I added other cameras. Then I noticed that some of my actors, that could act as pawns, weren’t showing up. So I added them to the sequence. Still wouldn’t show up. Okay, so I figured there might be a flag not being initialized – I added a track for “actor hidden in game” and it was false, I made it true. Well, then I’m thinking; what if this is happening to the camera?
So, I add a track to my camera sequence and turn on “Auto Activate” – suddenly, what I see on the camera starts showing up in thumbnails on my camera cuts!
Usually my sequence master track is set to autoplay in the game because I’m sequencing FX. So, I guess since I was just throwing in a cam to shoot an image with MoveRender this showed up. Also, prior to that, I’d had a crash when movie rendering and that’s when I exported what I needed to image to a brand new project. I’ve had this happen in both UE 4.27 and 5 – so it might be after a crash, the “Auto Activate” flag is off on the MovieRender cameras by default and thus, it doesn’t show up to UE as an available camera.
The other thing I do of course is check to see if cameras are assigned to the cuts, and on “edit section” I always want to choose “Keep State” when section is finished.