Help! Can Am Renegade 800 2007 jerking on decelleration

Hello Everyone, i own a Renegade 800, model 2007.
In the recent months I experienced a jerking on decelleration, around 30kmh .
The problem got even worse if i am riding with a passenger or with 4WD.
Attempting to solve the problem I tried to inspect and clean the clutches.
I replaced the one way bearings,
I replaced the primary clutch rollers.
Changed the belt with a new one.

Nothing worked.

Has anyone experienced this problem? Is there anything else that I can check?

Thx

Federico from Italy