If you reflect an enemy Unstable Concoction while you yourself are currently brewing a concoction yourself, your concoction gets canceled completely. Furthermore, the reflected concoction stuns and damages based on how long you were brewing yours, instead of being equal to the enemy's concoction.

Repro:
1. Pick Alchemist, level up Unstable Concoction and get Lotus Orb
2. Create an enemy Rubick and steal Unstable Concoction
4. Cast Unstable Concoction on Rubick
5. Few seconds later, start brewing your Concoction with Alchemist and cast Lotus Orb on self
6. Target Alchemist with Rubick's Unstable Concoction

Result: As soon as Rubick's concoction lands, it gets reflected. This causes your brewing to cancel completely. The damage of the reflected Concoction is based on how long you brew your canceled one.

Expected: The reflected Concoction should not interfere with your currently brewing one. The damage and stun of the reflected Concoction should equal the Concoction which hit you (this is the behavior when reflecting it while not brewing one yourself).