Motion NBT Tag is broken for players

I created a contraption which is supposed to set any entity's score of an "isMoving" objective to 0 if it has a motion of

{Motion:[0.0,0.0,0.0]}

(if it's still), otherwise the value defaults to 1.

Unfortunately the value is constantly set to 0 even though the player is moving, unless you're sprinting + jumping at the same time. But it works for mobs.

This ruins a quick way for mapmakers to determine whether the player is standing perfectly still or not.

See a video of the bug in action here : https://youtu.be/lkKwvwwA0xo