Hello, I think it was addressed quite lengthy before.
They adjusted it so that it doesn’t trigger on non-imbued attack which was happening before. But it seems for TB, it doesnt trigger on the return and rotating blades created from Bladedancer’s Aspect…it only triggers on initial stab.
The way some people combat for the lowered Bursting venoms proc rate is to swap out one of their aspects to Aspect of Pestillence Points which can trigger Bursting venoms.