When entering the world with two characters from different accounts the bag sound does get played each time since more than a week. The chat window and the inventory do not give informations about the reason. No item had been added. This happens since each of those characters had received a Sealed Tetradrachm Coffer from the Frostfell Overseer achievment. It is still in their inventories and enough space is available. No items are on the cursor.
It started happening when they put the Key achievements in the game. If you have keys you haven't "poofed" yet, or keys to achievements that have multiple keys (like ToFS) you haven't finished yet, you'll get the bag drop sound. I had multiple toons with "unpoofed" keys in their banks/houses and once I took care of them, the sound stopped. However, once they added the new Overseer achievements associated with the seasonal events, the problem came back. I can only assume it's caused by either the achivements themselves (maybe unfinished achievements?) or having unclicked rewards (currency, agents) in your inventory. There are 2 or 3 older threads about this floating around. They barely addressed it and never fixed it. Honestly, I no longer care if they fix it now or not. I've come to accept it as one of the many bugs they either ignore or don't know how to fix and won't admit it.
