Lag spikes with no ping at all?

Hello, so I have been playing League of Legends since season 1 and never before have I experienced something like this. So, i never had trouble with lag, my internet connection has always been quite reasonable. I usually play with 50 /60 ms never more. I have experienced lag however when I am downloading something and my ping gets to 300 ms more or less, but after i cancel the downloads it goes back to 50ish, this kinda lag makes your playstyle slow and you noticed something's off, recently however, my ping as usually does not exceed 60 and i get lag spikes constantly, the playstyle does not feel slow, it just stops, the animations stop, the sound stop for a split second and then i reappear somewhere else. It's been getting worse and i have died a couple times because of this problem. Note: The ping DOES NOT exceed 60ms Note: This is the only game it happens with, maybe something wrong with my or Riot's connection?

Please Help and thank you for reading