Hi Alex,
Don't panic, let's check a few things. I have seen a that kind of thing where I set a value for the Maximum/Minimum for my Expression pedal and it jump back to what it was before I was able to lock in the changes. This is usually because the voltage value being measured from the expression pedal itself changed. Sometimes I bump the pedal or it may be the potentiometers in the pedal itself aren't that great … who knows.
I suggest this, temporarily unplug the pedal and make the settings changes. Test it with the Ribbon, and then plug in your pedal again and try the settings using the pedal.
This may not work, but I think it just might!!!
John