Hi, I'm still pretty new to mahjong, so I might be completely wrong here, but I just got this hand--I declared kan, and drew the final tile in the wall, which was also the winning tile. Therefore, shouldn't this hand be considered a dead wall draw, and actually be worth 3 fan, with the payout being 1600/3200, rather than 800/1600? If I'm wrong, I would really appreciate an explanation of how I'm wrong--since I'm still learning how to score hands, I'll take any learning experience I can get. Thanks for any help!

Yes, this is a bug (scoring error). This hand wins on a replace tile, which is the last tile of the wall, after an exposed kong. This shall be considered a "After a Kong" or "Under the Sea", each is a "One Fan Yaku". Adding the "All Triplets", it is 3 Fan in totoal.

The hand is here for future referrence.

Awesome, and thanks for the quick reply!

Edit: actually, is there a difference between under the sea vs dead wall draw? From what I understand, having an exposed kong immediately before drawing the winning tile makes it a dead wall draw rather than under the sea, but again I’m still learning and could definitely be wrong lol

From the riichi rule, I find that After a Kong does not combine with Under the Sea. So the Fan will be the same anyway.