Maybe that's an indicator of "You have to change FLASH chip ASAP until you lost your calibration" ?
The one thing that is not clear for me, has it worked before ?
I have meter with revision 06, I tried to (save, power off-on, setup factory, save, power off-on), and custom settings appear on boot.
If you are going to replace FLASH chip, dump CAL coefficients first before touching it, just to be on the safe side.