Underwater Cave With Missing(?) Chest

There is an underwater cave at approx. -29, -3578. When you enter the cave there is a camp with a skull on the ground, going left from this point will bring you to a locked iron door while going right will bring you across a lily-pad path to a sign that reads: "I have to hurry to the chamber... Before it's too late..." By clicking this button then rushing back, you can enter the iron door into a room with piles of gold, emeralds, and a pedestal with a pillar block in the middle; however, there is no chest on this pedestal or anywhere else in this cave. I'm wondering if this is an issue specific to me or if there is just no chest there in the first place??

 

Someone migth've looted it before you.

 

I stayed around the cave for about 25 minutes, I didn’t see anyone around the area either.

 

I just randomly found the cave too, I first thought I miss somethings, like a timing or a hidden things but it just looks broken or unfinished