This result could change physics forever

Here's a thought.  Same magnet.  Same test process.  Same planet.  But different locations.  Was there a difference in the altitude of the magnet installation sites?  NIST particle clocks experienced that as a numerically measurable difference between the clock installation altitudes for Boulder, CO (higher) and Gaithersburg, MD (lower).  They later discovered they could numerically measure the tick difference between two shelf levels in the same equipment rack.  They now average between multiple clocks at different rack elevations, and slightly different locations as well, just to be sure.  What about the density of the bedrock between the two magnet sites?  Could it simply be a minute difference in gravitational field strength for the two magnet sites that produces the different value?