Mode: Evac, Solo. This happened on the last mission (Defend)
Description: At the end of the Defend mission I noticed something strange. As I cleared the Second tier mastery I unlocked a blank badge.
Mode: Evac, Solo.
Description: I unlocked Laz some time prior to yesterday, but my mastery was reset for the Med gun and Tranq darts. When I cleared Level 1, Level 2 mastery for those two slots was at 100%. Not game breaking, just odd.
Let me know if you need more information.