The Game is Different, Depending on Where I chose to Initiate Play

My game behaves differently depending on whether I choose to play the game from the level, or from an actor blueprint. Here is a demonstration of the problem: Different Game Behavior in UE4, Depending on Where Game is Begun - YouTube

You will see that, when the game is played from the level editor, the enemy (guy in white) goes flying all the way to the back wall, when hit. When this same level is played from the enemy’s blueprint, however, the hit does not send him nearly as far. The version that is played from the blueprint is the closest to the desired effect. It is accurately implementing a ‘counter-force’ to the hit ( shown here:

).

The version played from the level editor seems to ignore this counter-force, and so the enemy takes the full force of the blow. This is not desired.

How could I go about aligning what looks like two different versions of the game? I have tried deleting the enemy from the level, and then putting him back in. I have tried duplicating the level, in case it was corrupted. Nothing has worked so far. I would really appreciate the help.