Problems with Arcane Comet?

I noticed after the last patch that the tooltip that states the percentage of how many comets have hit, gives a much lower percentage than it used to. To verify if this was true or not, in a recent jhin game, at the start of the laning phase, I hit an opponent with dancing grenade, proccd comet, landed said comet, and then when i checked my stats, it said I had only hit with 50 percent of my comets. Yet I only fired one and it hit. It's also important to note, that during that whole game, the accuracy of my comet hits never rose over about 36 %, yet I know I was hitting way more than that.

Is there any explanation for this?