One thing to try is to use the BotP gem along with In Geom, since both have the same required trigger in order to proc. If the gem triggers but the IG doesn’t, then that shows that a bug exists. If neither triggers, then you likely didn’t kill all the minions.
Not sure if you read the above posts or not, but they are specifically talking about blue packs where the progress orbs drop, and In-Geom does not proc. There are no other minions to kill.
That is what is shown in the video above. What is not shown is whether or not he is actually using In-Geom or not, but I think he would have noticed if he were not using it at all, since it is a crucial part of that build.