Support Specialist Tier 3

To complete support specialist challenge I have to deal 2,000 damage with the incendiary airburst launcher as support. In game I’m seeing 70+, 90+ and kills that reach 200+ at times in damage, but when I leave the game to check the progress it’s progressing like 2 points a game. I’ve played nearly 10 matches or more now using only that camping supply bags and it says it’s only at 66/2,000.