Spark stops hitting bosses mid-fight in T15 maps with Blood Mage

Bug report reference # 2,937,699,913

This happens to me in approximately 1/5 maps. In the middle of the map boss fight spark will stop doing damage to the boss. It doesn't resume damaging either, so I have always died, because of the bug.

I try rolling repeatedly and using other skills, but the Spark damage does not resume functioning properly.

I'm using T15 maps with 3 paranoia instillations and 0 additional attempts. I have several other high level characters, which do not have this issue. It only occurs on my Blood Mage character.