Eldritch mobs mod spawns special variants of the mob, and consequence of that the enderman endermite farm is ruined, the special endermen kill the endermite from a distance using fire charge (ghast attack) or some other random method, its random every time, i even encountered cob webs spawning, poison, random fires set on the endremite. I would prefer that the mod would be removed from the modpack or at least fixed somehow, either way i will be removing this mod from my server and game files.

make sure to use a lever or something to "turn it on". the quest tells you this as well

soothing lanterns will prevent this in the chunk you place the lantern. put soothing lanterns under your farm. There is even a quest for this...

Ou... My bad then, i recently updated to 1.9.1 from 1.4.4 and never used the mod, i saw other people experiencing the same problem and one of the players even encountered a problem where they did place soothing lamps and it did not work. I will try doing it myself and see if i wont encounter the same problem.