I've already bug reported this, spoke of it before, yada yada but it still seems to fall on deaf ears, so I'll try this section to get dev attention.
When a cleave resets my momentum swing and when a momentum swing resets my lay waste, sometimes the ability does NO DAMAGE but only shows the animation.
You can reinforce this by using resetted MS/LW's to charge your blitz for example, and they don't add to the counter because they aren't actually there. When they are, they add to the counter.
You can also reinforce this by using the appropriate trigger, seeing the momentum swing or lay waste appear colored again (suggesting its ready for use) but a subsequent tactic or cleave places it right back on the cooldown timer it was on before.
This doesn't happen to 100% of them, some actually work - but the majority in my experience are fake resets and its incredibly annoying when you plan on using it and it does nothing.