Level Sequences can't reference actors that reside in Level Instances different from the ones they are executed from.

Level Sequences can reference many actors, but the references are not solved if the actor is not in the same Level Instance as the one the Level Sequence is being played from, or the root level from the hierarchy

Create a world partitioned map
Place a cube in the scene
Create a level sequence that animates the transform of the cube
Place a level sequence actor in the main level (not within the level instance), link the level sequence and check `autoplay`
(Optional)Default behavior: PIE and observe the animated cube
Put the cube in a level instance.
PIE and observe the sequence playing, but the animation is not.
The Cube will show up red in the Sequencer window and a hover message will say "The object bound to this track is missing"