Hi, can anyone throw some light on my problem here with Audya 4 module -same as Audya 5 keyboard but no keys

When i try to assign the voices seperately via 1234 outputs I put the Kick to output 1 and then the snare to output 2 and then all other voices to 3
I press save so hopefully my changes will be saved. However , when i turn on the audya next time i find that it did not save my new output settings
Where am i going wrong?
Any help greatly appreciated as usual