High server load because of 12,000+ people playing can make the chat shady and prone to disconnecting. I’ve had periods of continuous disconnects or really laggy chat before, and during those times, I’m always careful about going for badges. On the bright side, Kong is in the midst of a server upgrade, if I recall correctly.
When I finish a badge, I wait on a victory screen until chat pops up something saying I have the badge. I usually don’t refresh and hope the badge appears. My rationale is that if the badge never does show up after the refresh, I can take a screenshot that proves something.
So basically, be careful if chat is massive laggy or disconnecting frequently, and wait at the victory screen of a game until the badge is awarded.