There is a unintended bug i believe when you skip the checkpoint in a delve, die a bunch of times, kill the final boss, wall back to the checkpoint and claim the extra life, and then walk over and claim your bountiful chest. This seems unintended and boss death probably should lock the loot to being what its suppose to be. Reddit has been discussing it for a while it seems.
I know this is a serious bug report, but I genuinely laughed at “bluntiful” delves.