Whatchstone's bug - Conquerors won't drop the last 3 stones

At awakening level 6, one of the conquerors did not drop the stone. After killing Sirus, the next conqueror's round, some times they will drop the stone and other times not. After many many rounds (And killing sirus) the bug continue. Only left to drop 2 RED and 1 YELLOW.
At this moment i have Awakwning level 7. Impossible to get level 8

I'm guessing you know that there is only one stone of each color from each region. After you have 20 stones, the conqs will spawn whether they still have a stone to give you in that region or not. This is so you can progress the Sirus cycle.

You need to spawn the conqueror in a region where you do not yet have a stone of their color. This means there are only 2 regions where you can get a red stone and 1 where you can get the yellow.