Sorry for delayed response Joel – I started drafting a reply thinking about what could go wrong and got distracted.
There are two slightly different hardware versions in the wild, and I think it sounds like your meter somehow got confused about what kind it is. You can see what kind you have in the silkscreen on the bottom of the PCB: RevH or RevI.
RevH has a 1.25V reference voltage. RevI has a 1.21V reference voltage. I’m guessing that maybe you have a RevI that thinks it’s a RevH – that would make all readings go off by a factor of 1.25/1.21 = 1.033 or 3.3%. The resistance measuring circuitry also changed quite a bit, if my diagnosis is correct your resistance measurements would be totally bunk. Is that the case?
I haven’t dug in to the app history but I see you’re using Android app version 1.0.17. Can you try reinstalling firmware from release 19 (app-release-19.apk in the directory I linked earlier) and measuring again? Sorry for the trouble. Release 19 is the present production release.
Regarding theory of calibration data wiped: I can assure you that didn’t happen because the meter would not function without it.
Sorry this got long – thanks again for the excellent feedback. User feedback drives product development. Let me know how it goes – if the firmware update does not fix the issue email me at firstname.lastname@example.org and I’ll handle the return.