„Sudden lag“ in ranked 1VS1

Hey guys,
I have been playing a bit 1VS1 ranked and I always noticed something.
In like 60-70% of the Matches I played with players with a low ping.
But all of a sudden they start to lag, like their ping jumps from 18 to 200/300 back to 120 and so on and ofc i get killed since they teleporting around or else etc.
this is happening a bit too much because I sometimes played against Egys or other people with a 50-70 ping, even 110 pingers and their ping was always constant and they didn’t lag around or were harder to kill.
It’s definitely not related to the servers lags since my ping kept being low at around 13.
Yall experienced something like that too? I think that they are doing it intentionally to gain some unfair advantage.