Board Game Arena

Hey, can anyone explain to me why I lost the second round (and thus the game) ?
Here is the game link : https://boardgamearena.com/table?table=779195494

It looks like a bug, and if so I'll move this post to the correct section, but maybe I didn't get a rule correctly

You lost because the program is buggy. If there is only 1 tile left, it often doesn't count points, but determines the winner based on whether the player can remove the 25th tile. The bug has been reported by several people: https://boardgamearena.com/bug?id=189151