The cache IS at the listed coordinates.
In order to qualify to log this cache as a find, you need to find the cache and sign the log, plus accomplish the following challenge:
The green colours of the backgrounds of the numbers in the Difficulty-Terrain Grid get darker when you reach 11. Find 11 caches in each of the 81 grid spaces on the DT grid, turning every square to a slightly darker green, in order to qualify.
You may use the Project-GC checker below to see whether you qualify. If you wish, you may post a screenshot of your darker DT grid showing all the numbers 11 or higher.
