1) check - that was my first thought and everything looks good
2) so originally with the service was published and cache was the path for the imagery was the local drive, ie: c:\imagery\tiles
a. i later adjusted this to a UNC path name and republished the service keeping the existing cache
3) this environment was running 10.2.2 and was upgrade to 10.5.1
a. could this upgrade has cause some issues with rebuilding certain parts of the cache?
i have never only seen one level not sure, its usually been an all or nothing in my experience.
Dave