Minor Malzahar bug on Nexus Blitz (and maybe other game modes?)

I play a ton of Malzahar, and one of the big things I like about him is the way his E DoT Maelific Visions can spread from minion or champ to another minion or champ when the first one dies, as long as the DoT is still active. For some reason on Nexus Blitz in the middle lane minions will sometimes die but not spread the E. Then after a few seconds or so suddenly my E will spread to a new champ or minion out of nowhere. I think its the river in the middle of the map that causes this. Its very hard to reproduce, but I have seen it in about 5 games now. Next time I see it Ill remember to save a highlight of it. This bug is very minor, only a champ suddenly getting my E on them from seemingly nowhere may make some people angry.