Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Got a commentator badge today. Though my activity tab (filtered on comments) shows only 8 comments. Either the 10 comments limit has changed or the SO App was generous to me today. Thanks for the badge, don't take it away :)
In addition to those 8, you have comments on 2 posts that have been since deleted here and here (visible to 10k users). The badge is behaving correctly...it's just that comments on deleted posts won't show up in your activity tab.
Enjoy your badge!