Sound like a root motion problem.
I never did this without a playable or npc character but it should still apply.
When you create a character and let him jump forward for example you will need root motion animations or else the animation will play, the character jumps forward and snaps back to its original position this happens because the capsule of given character does not move with the animation if you activate root motion (in your animation blueprint) the capsule will move with the animation instead of staying at its place.
You do need some setup for this. but its completly doable in Ue4 (without too much work)
Just search for a root motion tutorial on youtube (sadly im too stupid to recall everything right now 
)
Hope it helped