The same happens also with the first two communities of the Active User Growth category:

• !business@lemmy.world, Business, 2 →828, 333 posts (331 this week)
• antennapod@lemmy.ml, Antenna Pod, 2 →828, 333 posts (331 this week)

The stats themselves also seem to be off for both: !business@lemmy.world may have gotten so many active users but certainly not 331 weekly posts (unless they got mass deleted since). !antennapod@lemmy.ml appears to only have two posts in the whole community, so both user and post numbers are probably miscalculated.