Player Controller jitters on colliding.

Hey guys! I am playing with cool controller i found.But it has some mechanic "bugs" that is affecting hard my game-flow.
For example - when i collide with gameobject and try jump, the whole controller jitters instead of just "not be able" to jump for example.Also i decreased my slope limit to 20, because i didn't wanted my character to be able to climb high terrain mountains.But when i tried to go higher the controller is backdrawing. Here is the video of my problem:

Any hints and help are appreciated <3
Thanks you in advance guys!