I'm still stumbling around with the PA3X and am certainly no expert. But I do know that if you press any of the four STS buttons the keyboard will revert to the settings that were last saved to that STS button. That action is not affected by whether or not the STS button is lit. So, apparently you have not properly set up and saved to the STS buttons the settings you want to use. See pages 136 - 139 of the manual.