Summary
with at least 5 points in the Warlock - Cauldron of Blood passive, the bleed overload bonus effect does not activate during combat after building up at least 25 (or more) stacks of bleed.
As a result, the bleed overload icon does not appear on the UI and the rip blood effect does not proc.
Notes:
My build uses all the other overload passives and so far they all function as expected.
I have observed up to 50 stacks of bleed and still no effect