Important bug with sticking to the terain

[Handel]

I am a horse archer and after the patch I several times was hit and then was stuck and immobilized for several seconds. At first I thought it may be due to the terrain and I just couldn't quickly move in the right direction. But then started to watch more carefully and the last time it happened on an almost flat place - no slopes, no bushes, no rocks, no trees. And if I am hit several times in succession I remain sticked untill I get knocked.

Edit: And this is not because of the hit itself - I know how much time is needed to overcome the hit.

2nd edit: This don't happen to all terrains.