confirm, the problem is on lyra2z. On phi2 or any other algorithm 3-4% deviation with calculators but not 27%... And about the fact that the calculators specifically do it - it's not exactly, just the Lira was apparently not designed for such a power network, and now there is an error in the calculation of complexity.... Generally when podseti arrived at лиpe2з necessary from the final profit take 27% 
Problem in a pool. If it is impossible to set difficulty, there will be a fall of profit.
Minecore.pro there is an opportunity to regulate difficulty. On ravein everything is good, but on gin for some reason there are no payments. If who knows still pools where difficulty can regulate, tell about it please.
On the picture two 8x1080ti from the set difficulty, and 6x584 (20,5Mh) difficulty appointed by a pool.
https://ibb.co/gUM82T