[Elecraft] KX3 Power output calibration

[brianstevens1 at btinternet.com]

I've calibrated my kx3 to a new kxpa100 successfully on all bands except 
10Mhz, where TX Gain still shows the factory calibration value ALC a1.9.
I've retried several times and can't get it to show a value ALC t X.X, 
any suggestions why this may be please?
The output at the amp seems to agree with the power setting on the kx3 
(as far as I can tell from the led's).

kx3 s/no 6738 firmware 2.90 installed
kxpa100 s/no 2814

Regards
Brian
G0WZX