Key touch setting on FP-10

[aamadis]

I know that you can change the keyboard playing feel (key touch) by holding down the function button and the F5 through A5 keys. But whenever I turn the piano off and turn on again the setting reverts to the default medium setting. I've seen posts here referring how to change the setting so this does not happen on other Roland models, but I can't figure out how to do this on the FP-10. How can I get the piano to remember my key touch setting?