I see a few things I would play around with:
First, try the Play from Start node on the timeline - it may not be resetting properly. Another thing to look at is the alpha…how long is your float curve?
And lastly, you are setting your actors rotation to Yaw: X, Pitch: 0, Roll:0, which may work fine, but you are always resetting the Pitch and Roll. I would use a GetActorRotation node and plug the current values into the Pitch and Roll nodes in SetActorRotation.
Hope this helps!