Solo mining flux- Same mega miner coming in and out finding most blocks

So I'm trying out my luck by solo mining flux. Though trying to get a better understanding of "Personal Luck", I did some digging around the site (2miners) and noticed that the same miner(s) seems to creep in and out from time to time and when they are mining, they seem to just be scooping up a good portion of the awarded blocks. After I find a block (current "luck" is 6% after 1 day) I'll probably move back over to pool mining. But in the meantime, I'm just curious as to why such a heavy miner comes in and out like that... seems like certain times too.

EDIT: forgot to mention that my current hash rate ranges between 130S/s and 80S/s... These mega miners who come in and out are mining at anywhere from 4kS/s to 30kS/s. Also forgot to mention that every time they come in, my Personal Luck goes down like 1-2%