[Kynim]

Bug: Entering a RUSH dungeon and finishing it without dying will teleport you back to the dungeon if you are knocked out in RPB, or killed by a different type of mob automatically. This will even rip you out of an RPB!

The only way to exit a RUSH dungeon right now is to complete it or be defeated as far as I'm aware (this might change in the future). This sounds less like a bug and more you were manually teleported out, unless I'm missing something. More details needed.

To be more specific, I was in an RPB with a player who finished one without dying, and after they fell in a round of the RPB they were teleported to the exit of the dungeon! They had already finished the RUSH dungeon.

This also happened to me and someone else while doing a normal dungeon (with a caves key), and we were denied the experience/coin because we were not near the boss when it died.