[meleeNut]

Same here,
I had reset all my quest files(deleting and restoring the quest and associated files) and was diligently running Scorpion boss, Gorgon queens, and Bandari with no problems. I probablly did around a hundred runs with my rebirth point at Olympus (legendary).

I decided that since I was not running Typhon to use the rebirth fountain closest to the Gorgon Queen cave(ran back after killing the queens). When I did that and started again all five chest were then gone.

So it does look related to activation of some rebirth fountains. Sure hope they fix it in the coming patch.