Your product is measured at one location and is within the specification, after being delivered to a second location and measured again, it is now out of specification. what could be causing your device to be measured out of spec in one location and within spec in another?
I think this can be two broad categories:
Something happened to the product during transportation which changed it (environmental, damage, chemical, etc)…We can try to get the product shipped back to the first location and measured there to confirm if something happened to the product during transit.
The measurement method/equipment at the two locations are different. (different measurement equipment, calibrations, measurement procedure)…Generally this is where doing some kind of correlations study between the two locations is helpful to make sure the two locations agree on measurements on the same exact part independant of all other factors. (GRR, kappa, etc)