[Gameplay] Malzahar's Malefic Vision fails to cast, Takes mana and goes on cooldown.

I have played Malzahar since season 4 and till now and I can safely say that I am quite a dedicated Malzahar main (even though I only have 100k mastery on him). What I notice about Malzahar however is his E mechanic sometimes can be broken. These are some of the problems I encountered while playing him even in my recent games :

1. His E ended sooner than expected (Probably my sense of perception fails me or my hearing fails me but I swear this is a thing, not a major thing and I don't expect this to change at all)
2. His E will sometimes fail to cast on a dying minion, goes on cooldown, takes mana, and does not spread to any other minion even though there are minions near the dying minion.

Number 2 is the one that I am highlighting however since this is a massive bug that I have faced multiple times especially recently. This sometimes made me lose lane pressure and can cost me the lane (although, this is silver games we're talking about). I do not think that this is an intended interaction.