Movie Render Queue doesn’t provide any API for us to access the resolution of the render. So if it’s not a standard 1920x1080, you can run into problems with aspect ratio or resolution. I’m not certain that’s what you’re seeing here, because you haven’t provided any details of your setup, but it’s my first guess. If that’s the problem, you can use the CesiumCameraManager to work around the problem. Instructions here:
The other thing to check is that your LevelSequence is in your level, not just an asset in the Content Browser. Only when it’s in the level will Cesium know to wait for all tiles to load before allowing each frame to be snapped.