Krone FC 320 Front mower issues

[pappuller]

We have a 12 month old fc 320 moco front mower and I have noticed this last day or so it is tending to flick grass out of the side whilst mowing shorter grass for zerograzing. It will do this randomly whilst mowing and leave a line of spread grass 2/3 metres from the swath. I had heard of an issue of grass accumulating between the disc and top hat and been thrown out randomly, anyone else have this issue and or solve it or is it just my short grass ?
Thanks