Blitz slow

I dont know did anyone encounter this thing but by me there is some kind of a bug or error only when i play blitzcrank.Its about annoying slowes that applies out of nowhere while u casualy walking around.At first i thought it is because of jungle monsters or creeps maybe that i attack with my ult, but then it slowed me in the middle of our base(base was untouched by enemies).This thing apllies only while i play bltiz and that`s why avoid playing him any more.