I was in the Wine Cellar with two guys from another clan, and the “Press to Interact” notice kept flashing on my screen. Having read about hidden chests, we broke up rocks constantly, finding nothing.
I happened to be standing still when the message flashed again. So, two of us stood still while the third walked up to a lantern to light it. We all got the same message at the same time.
It appeared that if one got it, we all got it.