I've found if you use it after a light attack it will connect, but after a medium it gets blocked. I know this shouldn't be this way but I doubt they will fix it soon since it has been this way for years now.
I used SIM to get me through act 4 and remember starting to have issues when 12.0 was released. It has been on and off since then. I only really use him in arena as well since I stopped using SIM and IM around 12.0, but I stopped trusting his L2 would connect after a medium.
Comments
Storm breaker
Not even
Thanos...
Wait I aimed for the head