[Gameplay] Bandit Mastery in Game Gold Count Not Accurate

When attacking other champions, the +3 gold will flash and the icon will appear to show how much gold you have earned. It fluctuates throughout the game but I have never seen it above 12, despite harassing like a boss. The count will also restart sometimes, particularly if switching between attacking the support and the carry. It's not really a big issue, but I'd like to see how useful the mastery really is by seeing how much gold I have actually earned through it. Thank you in advance for looking into this!