Haven't found it documented anywhere but tests on my M8X show that making changes on the 'Utility -> Settings -> MIDI I/O' screen followed by a power OFF while still on that (or other) Utility screen does NOT preserve the parameter changes.
1. Power ON
2. go to 'Utility -> Settings -> MIDI I/O' screen
3. observe that 'Local Control' is ON - change it to OFF
4. Power OFF
5. Power ON - revisit the screen
6. observe that 'Local Control' is ON - the change to OFF was NOT preserved
Test #2
7. change 'Local Control' to OFF
8. use the EXIT button (or other method) to leave the 'Utility' function
9. Power OFF
10. Power ON - revisit the screen
11. observe that 'Local Control' is OFF - the change to OFF was preserved
The above results apply to parms on other tabs/screens on the Utility section: knob flash, knob brightness on the System tab and parms on the AUDIO I/O tab.
I haven't done an exhaustive test of every tab/screen/parm in the utility section.
Q1 - is it documented somewhere that you must leave the Utility section before a power OFF in order to save utility changes?
Q2 - do tests on a classic Montage give the same results?
Using classic when I tried to make changes to the quick templates, they didn't seem to save. I didn't seem to have the same problem with other settings but I may have not followed exactly the same steps for both. Maybe your observations apply. I'd have to take a second look and try these M based suggestions.
Current Yamaha Synthesizers: Montage Classic 7, Motif XF6, S90XS, MO6, EX5R
Exiting the Utility section makes all the difference.
Using classic when I tried to make changes to the quick templates, they didn't seem to save.
That is what happened to me. I was doing some testing for Daniel's 'different process for record arpeggio to daw' and got 'local control' changed to OFF but then couldn't put it back to ON after a power cycle.
I just happened to discover the 'fix' accidentally later when I had set 'local control' back to ON but then left utilities to do other things before turning power OFF. Then, to my surprise, when I powered up 'local control' was still ON and it took me a while to figure out why.
The 'Quick Setup' screen has a 'Store Current Settings' button but, curiously, that doesn't allow you to change the 'Standalone' template.
On the M8X -
1. To save changes to 'Standalone' template you MUST exit the Utility section before a Power OFF event or the changes will be lost
2. To save changes to the other templates you MUST use the 'Store Current Settings' button before a Power OFF event or the changes will be lost. Exiting the Utility section will NOT preserve changes to the other 3 templates - only the button will.
3. Do NOT select a template after making changes you want to preserve - selecting a template loads the stored template settings so may subvert the changes you were trying to make to the template.
Make the changes (e.g. 'Direct Monitor' on the Audio I/O screen) return to the 'Quick Setup' screen and use the 'Store Current Settings' button and select the template from the dropdown - do NOT select the template from the screen before pressing the button or the changes are lost.
Not sure why they don't add 'Standalone' to the dropdown so that you can change that template using the button.
Utility -> Settings -> System parms are a mixed bag.
The bank, page and slot for 'Initial Live Set' are auto-saved when changed even with an immediate power OFF.
But after changing any of the other parms you will lose the changes if you don't exit the Utility section first.
This is for an M8X - don't know about M6/M7 or classic Montage.
Sure makes it hard to know what is saved between shutdowns.