Cherries may be small due to late spring, drought, or too much fruit. Usually it's too much fruit.

So even cherries can need thinning although it's usually easier to reduce the crop by pruning more aggressively the year before. After or during those yrs when there is no crop you might want to prune heavily. As soon as you can tell the crop is gone, take off a third or quarter of the oldest wood.

The fruit does stall out while hardening the pit before final swell and color change. So it might just be the stage of growth.

Where in KS are you that you get any sweet cherries to survive? My northstar and balatons put on lots of cherries even though the balatons are too young.

Sometimes I think crappy pollination leads to small cherries that never develop. I had this happen in the past and figured that is what it was...but wasn't 100% positive.

I live in Dodge City. I had people tell me I couldn't raise sweet cherries here, but when we moved here 47 years ago the neighbor had one so I figured I could too. This is the 2nd tree, the first one froze in the early 90's when the temp fell 80 degrees in one day in mid Oct.
This tree was pruned rather aggressively last year .