Question about treasure quest

[wasz_kapitan]

Hi all!
I'm URW long time player, visiting and reading forums for 2 years, but now it's my first post
I got a problem with treasure quest, which I completed.
The trasure should be on cliff, in deep chasm.
I found the region, found the cliff (there's only one - I checked region from border to border), but there's no treasure.
NPC said it should be "casual wealth of Islander region" (dream about masterwork Ango;)), so I checked the cliff tile by tile, every hole in the ground.
So please tell me - what I do wrong?
Maybe I should back there with shovel and dig? Maybe cliff could be the hill or mountain? There was a map maintenance in my game - it's possible that cliff was "reseted"?
I'll be grateful for any advice.

[PALU]

There have been issues in the past with map maintenance removing treasure, so it's not impossible. I think it's possible for someone else to stumble upon the treasure and take it as well.

You can't dig on a cliff (rock is hard!), so the treasure is just stuffed down in the crevice (i.e. there's a pile of items on that tile).