I noticed the same thing as singletrack, and for the same reasons. In my case the fix was to rebuild the table it was mounted on to stiffen the surface, square everything very carefully, and eliminate the gap between the rollers and the end plate. It helped tremendously. After running (literally) tons of grain through it in the last year it is starting to act up again. I'm going to have to look at it and see if I need that upgrade kit.
Take it apart and clean it. This should solve your problem.
I run about 2000 lb every month thru it and had to do it once.
Grain gets between plate and rollers. Then free spinning rollers will stop to spin.
That's exactly what I ended up doing, taking it apart and cleaning it. No issues since. I see you are running some fair amount of malt through yours. What size system are you milling for? I ask because we are trying to find a mill for our 7bbl system and are borrowing another brewery's mill. It's a good mill but we are hauling malt from our location to another and then back again. So we are looking for options and have looked into several different mills. I don't want to get too far off topic here and will leave it at that.
I have 5.5 BBL brewhouse.
I double brew in one day.
It takes some time to mill all the grain but it works quite well.
I run my mill at about 260 rpm. I could speed it up to 400 rpm.
This would save some time.
I have been using this mill 3 years now.