Bugs 3 protocol + Jumper T8SG - problem

Hi guys,
I'm having problem with my Bugs 8 PRO using Bugs3 protocol.
It is binding, control works, but right stick to the maximum position is making drone going "back and forth" in that direction.
Please take a look at this video:



With right stick at 80% in one direction, its behaves normally, flying smoothly.
I guess I have to cut that 20%, but I don't have knowledge to do that.
Please, can someone explains how to do that?

Best regards.