So this is rare but tremendously annoying

I get this thing every like 50 or 100 games or between but when it happens I don't know why and it's really annoying so what happens is that I play few games everything is fine, than I'm playing and suddenly my ping is jumping from 40 to 50 to 40 to 70 to you get the idea.... And this shouldn't happen like I'm playing on cable, when I pinged google DNS server I got 8 ms in average max like 12 ms but it's really annoying what can like cause this like some ally or enemy player lagging so hard it lags for me too or what is it? I tryed restarting game 2 times (it takes less than 20 seconds so it's ok) and still the problem remained it stopped for like 3 or 5 minutes and than it came back again and also I feel like it didn't lag at the earlygame because when I clicked it responded but 10 or 15 minutes into the game I click and after almost second I charge ability or switch direction on my screen everyone was ok and my character was literally lagging my Pyke ult literally moved after casting slightly like how?

Thank god we were ahead cause it was ranked...