Problem with bolt stack in private server

Hello, I spent a while using the bot with a rogue buying bolts for the xbow, during the process I noticed that in the city they are making more purchases, on my server you can stack 2000 bolts per pack and likewise you can buy 2000 at once.
The bot on the other hand buys packs of 250 and sort them, which makes the process in the city much slower, I appreciate your help.
Screenshot_2 Screenshot_1

Seems like an issue with their item stack quantity. The bot will buy the maximum possible up to the maximum stack then it has to buy another of the same item.