Using a flask resets crossbow ammo stacks to 0

Whenever I use a flask (mana or life) my crossbow ammo stacks are set to 0. This makes explosive shot/grenade combos difficult, and it renders hailstorm rounds essentially useless. This has to be a bug right? I can't imagine this is how the mechanic is meant to work. Currently level 56 Gemling Legionnaire. I've tried swapping out gear, support gems. Nothing works.

Note: I removed the Ammo Conservation support gem from one skill and it fixed the problem. I have the Reusable Ammunition passive enabled, perhaps a conflict between these is causing the issue. I would like to use both, but for now this is my workaround.