John Deere tractor and 335 baler

I just bought a 335 John Deere baler. When I tried to bale, after a small bale was made, it started kicking the door open. Someone told me it was the hydraulics on the tractor. Cleaned filter, put new hydraulic oil in, checked hoses. Door to baler closes very slowly. Still no luck. Anyone know what’s going on. First time with a round baler. Always had a square baler

John Deere tractor and 335 baler