So I made an interesting discovery. On my main server world including Ultra Space, End and nether Gameshark doesn't function properly (aka it struggles to keep tracking on one thing flickering from time to time)

I've made a separate world with the help of multiverse but still BoP to make zygarde cells finding easier since on the main world it doesn't work and astonishing enough on that separate world it isn't buggy at all. This makes you wonder what really the root problem of Gameshark behaving so weirdly in the main world is.

I've already tried resetting the main but without success (only wiped region folder & level files).