The cache is not located at
the posted coordinates.
Use the POSTED COORDINATES as a starting point for solving
the puzzle. (Note that this is different from other "On The Grid"
puzzles, which include a separate coord value.)
This cache uses an idea that is blatantly stolen from a very
nifty puzzle cache, Quadtree
(GC2M30A). But... stolen with that CO's blessing, and with his
help. In order to avoid any cries of "Unfair!" from all the FTF
hounds, he has agreed to help with beta testing, and will stay out
of any FTF frenzy.
The diagram shown below is something called a quadtree. I am
providing the same hint that was provided with the original
Quadtree puzzle cache to help you understand how that concept
works. My version has some simplification of the lines and boxes on
the bottom row, to conserve space, and has a little color added. If
you can convert the quadtree to a grid, you should see something
that fits the On The Grid concept; although you will have to fill
in the row and column numbering, based on the OTG example, or on
any of your previous OTG experience. To order the four solution
cells properly, search for something called Quadpixel. (What a
coincidence that I came across THAT!) Then use the coordinates of
the solution cells in the determined order to find the actual cache
location, based on details provided in "Get
On The Grid".
Have fun!

Congrats to Beege49 and
crosspa for a quick FTF!!