What does your implementation/code look like?
It may not be your animations but the state?
How does your code change from "falling" to "idle"?
Also, slightly unrelated but I have been working with state machines lately. It usually helps that anything that is some state different from the others become a separate state itself. If you have a transition, perhaps make it an additional "buffer" state to smooth things out. It could be a matter of states changing too quickly or "leaking" into other states because no logic is stopping it from doing so.