AI Cats counter?

[jasmine and irises]

Hi, recently I've been working on getting max number of AI Cats purchases to unlock the achievement. The counter in the shop shows 118 as the maximum number, yet it stops at 114/118, changing button text from “buy” to “max”. It unlocks the Steam achievement at that stage, so nothing to complain about.

I was just curious: why there's such a weirdly functioning counter and why doesn't it text change to “max” (like in other shop items maxed) but stay this way? And why 114, not 115 being the highest number?