Toril, if you are adjusting a style part voice then ckobu is correct. But if as you seem to say you are adjusting a right voice (or even the left voice) that won't work. You need to memorise the new settings to the appropriate OTS, (push memorise then one of the OTS buttons) after which the KB asks if you want to save the OTS. If you have more adjustments to make, say NO and do those first, and when ready to save and after being asked again, say YES.
John