Playing on PC in Operations Mode. Map is irrelevant. Bug is 100% repeatable.
CRS still isn't working post patch. You can take the serum in battle and you will receive the debuff, but it does not add any free max stat upgrades as the text describes. You do not receive an additional Max Stat Upgrade Point, nor are you allowed a Max Stat Upgrade for no XP cost. The item literally does nothing except debuff you for the battle.
Screen Shots: https://imgur.com/a/ElpF0pQ