Just had a match with Malz; while the E bug has been an issue for me for quite some time, the R issue is new with the most recent patch.
First, if you cast E too close to a minion's death, the ability goes on cooldown but does not apply itself to said minion. This has been happening to me for as long as I remember. To replicate, just cast E when the minion is seriously close to dying. Like really, really close. It's not happening ALWAYS, but frequently enough to notice. I'd say at least twice a day over maybe five different matches total for the day. Sometimes more or less.
Today R seems to have gotten the same type of problem. I cast it, nothing happens, and it goes on cooldown. Victim did NOT have Banshee's. At least twice in the same game. No void pool, nothing. I will attempt to record both issues and report back here.
edit 12/7: [E example](https://youtu.be/QtlIBbBcMSs)