Residual Boils & Theorum Infection

[AreeSoothsayer]

I recently paid attention to the new arcanes and found out about the pet buffs. I have makes ranks on both.

Here's the problem. Sometimes they work just as they should. Then other times there is no interaction at all.

Either I will run into the Infectious Boil and gain stacks of pet damage buffing or nothing at all will happen. I have been watching but I cannot see any reason for it to not happen.