The cache IS at the posted coords. You will NOT need to solve a puzzle to determine where it is hidden.
I archived a puzzle that was hidden here due to the key changing often. After the fourth time, I decided it was not worth changing the puzzle again. It had grown a little tiresome on my end, and I am sure it was for those trying to solve it.
Cache should be in the spot you would think to look first.
Good luck and have fun!