Best Seller Badge & Sales Rank

Hi, my parent listing is listed around 700 in parent category Home and Kitchen, my closest competitor listing is around 1200 rank in same category. However, in our sub-category, they are (now) number #1 spot with best seller badge and we are #2.

Is this possible? As I believed the number #1 sub-category spot is based on your parent category spot

If it is a glitch, should I report to Amazon? As the best seller badge was very important to us for sales