Earlier today I played a game as Gankplank, and reached 300 CS at 25 min, my very own record so obviously I wanted to screenshot is as an "achievement", but then I noticed I had 277, not 300, so I was like "Wait, What?!" I was pretty sure I had 300 because I looked at my CS literally 1 second ago and saw that I had 298 farm, either my eyes were playing a trick on me or the game was bugged. I believe that the reason to this was because the last 2 were the Krugs, so I started to investigate and jumped between lane and jungle and noticed that every time I last hitted a jungle creep my CS went down exactly 23 farm each time. I told the guys I was playing with because they obviously didn't believe me when I told them, and then we noticed that it didn't happen just for me. Not to mention, I had reached 400 farm at 36 min and wanted to screenshot as an another achievement, but didn't really get to, because when I noticed that I had 400 CS was when they surrendered the very second my bullet hit the 3 tiny Razorbeaks and then my CS went down to 364, which I didn't understand why because all the time it went down 23 CS, this time it went down 36, so I was really disappointed at the post-game screen seeing that I had 364 at the end, not 400. Tried then again with other champs but didn't seem to work, nor did I manage to reach 300 farm without killing jungle creep.
**TL;DR: **Killing lane minions then jungle creeps will lower your creepscore until you kill another lane minion, maybe was just because I had 300 farm without killing jungle creeps, maybe just a Gankplank thing.
Link to screenshots: