Chopping straw help

[Alwaysinit]

Cutting rape here atm and chopping the straw. As soon as I start cutting down the not very steep hill the straw stops falling into the chopper and blocks the walkers. What am I doing wrong and how do I fix it, no experience with chopping straw. It's on a NH tx65.
Thanks.

 

[Brisel]

Clean the panels that the straw slides down. Osr is oily and doesn't flow well. Unsprayed osr used to hang up above the chopper in a TX68 as the throat narrows.

Try speeding the drum up to smash the straw up more and see if that helps. Do it in small steps to avoid overloading the sieves.