Yes yes yes! If they are scattering feed out of the feeders it could be attracting nighttime critters which can bring in diseases and may also be predatory. Those critters are being well fed with excess feed which means healthy critter offspring!
On the same note, where are the feeders at night? All food should be removed from coop and/or run areas when chickens go to bed. Leaving them in place may be easier but it's an open invitation to an all-you-can-eat critter buffet. I leave water in the run but NO feeders. They come inside the house overnight. If you have a garage (I don't) you could put galvanized metal garbage cans in there and place your feeders inside with lids tightly in place.
You really are paying way too much to feed your chickens. I had 5 birds. In May I increased to 9. I calculate that if I go with rounding up to the highest average since the increase I spend $6/bird each month. Before the increase it was a bit less than $5. This includes feed, oyster shell, and grit available from sunrise to sunset, and for pine shavings and PDZ. So at $6/bird I'm spending $54 a month. For your 23 birds it would be about $138 a month. Do you have a Tractor supply and/or other farm supply type store nearby? Compare prices everywhere!
Synopsis:
Lose the corn, change to flock raiser, raise your feeders to the height of a chickens back, bring feeders indoors every night.
And let us know how it goes. We may be able to see other things you can do not only to reduce your costs but to also increase your chickens health!