Hello Michael,
There is a community post where a user described exactly the same issue that is happening to you.
You can see it here.
What is the output coordinate system you have selected in Pix4D exactly? Is this one?
If that is the case, the defintion is:
That means that for the Google Earth export, the conversion is using US foot.
Would you share the Quality Report? If you are using GCPs, are they given in feet or US survey foot?
Regards.