Flicker Strike only adds one combo?

As title says, Flicker Strike only adds one combo regardless of how many enemies you hit with it.

I wanted to try the idea of using mantra of destruction with flicker strike to empower it, then get enough combo from flicker strike to rinse and repeat but no matter how many targets hit, flicker strike will only add one combo.

I assume this is a bug but it almost seems intentional. If it is intentional, what exactly is the purpose? At the very least, add a line of text to the skill specifying it only adds one combo regardless of how many enemies hit.