I farmed for 2 hours in ShadowBlast trying to get Emblems of Nulgath (for VHL) and it seems that there is a bug whenever a room is glitched (the bug where you type /join mapname---12345 and go to the house). For some reason the Gems of Domination wouldn't drop from the Shadowfall enemies (The Fiend Seals from the Legion mobs were dropping tho). Considering i have been farming for 2 hours it should've dropped at least once. I closed Grimoire and restarted the bot again. In just 2 kills from the bot i got a Gem of Domination >((((((((((( This bug also happened when i was farming Esch Helm and for the whole 12 hours i ran the bot i didnt even get a singe helm (i checked the loot and it was all non quest drops)
I am unsure if bugging the room is the cause but there is something really weird about these droprates.
There are times though that sometimes monsters just refuse to drop items for some reason even if they are 100% drops. This is not caused by the Respawn glitch since it happens even in normal non-glitched rooms.
It's usually solved by clearing your cache.