I also get some massive lag spikes occasionally, where my rotation will act like its gone back in time, i.e. back to riot blade instead of at the end of the combo where it should be. Im unsure what is causing the issue, I did just move to a different house with a different ISP, so I am heavily leaning towards that being the issue, I just am unsure how to go about pinning down the problem. I don't seem to have packet loss, I have tried running a ping test during these high lag spikes, but it just seems like my ping goes up to around 150 or 160. I've seen 150 ping before though, and this feels more like 400 or so, given how hard of a lag spike it is. And then about 1 in every 2 times this happens, I get kicked to the lobby with an error 90002.

Any advice/help or what I should go after my ISP for, would be greatly appreciated.

I'm going to try the trial of pingzapper to see if that fixes the issue, that will at least give me a clue on it.