Health on hit Stops Functioning

[EbonYxi]

I don't think I've seen anyone complaining about this, and maybe they simply haven't noticed. But lifesteal in the current build of the game seems to randomly decide to cease functioning. The major abilities I've noticed this problem on involve KFM's grapple 3% health regen on successful attacks mid grapple, and BM's shoulder charge for 10% hp. (Mind you when I say lifesteal I just mean 'requires a successful hit, which we get, to give health back.) This is a VERY frequent bug, and I can pinpoint a ridiculous number of aggravating deaths and a few arena losses directly to "My ability mysteriously stops working despite no known CD and having worked consecutively properly at times before." Unless I am missing some hidden information in a tooltip about health on hit abilities, please fix this bug.