Tahm Kench Minion Devour not Dealing Damage

I recently played a game as Tahm Kench top vs a Dr Mundo. When I Devoured minions to spit them out for waveclear, about 75% of the time it would only deal damage to the minion I ate and not to the ones it was supposed to deal splash damage too. This only happened against minions, I would damage Mundo as normal if I ate either him or spat a minion at him.

This had a negative impact on my gameplay because I was not able to waveclear, I missed CS because of it, and the Mundo was able to freely shove me into tower so that I could be dove multiple times by him and the Elise. I have noticed bugs like this before but they were isolated incidents that did not affect gameplay too much; however, this bug was a contributing factor to my losing lane. I have also had a bugged Devor where I cannot eat allied champions without turning off smartcast, and that has caused me to suffer in real gameplay situations as well.

I hope that the bug team can look at Devour and fix what is going on.