In your code, you don't have anything setting "On Ground?" to false, only when jumping. You might think that your "if not actor hit a tile" would execute, but that is inside a collision event, meaning your actor would need to collide with something for that to happend. That's why your falling animation isn't paying in those cases.
Use the double-boolean setup to check when a collision is not happening instead. In the attached example, the "On Ground" attribute will return true if the actor is touching the ground, and false if not touching the ground.
