Tweak tool not saving and retaing audio output settings

Changing settings in the audio output area in using the tweak tool does not seem to save and retain the updated settings reflecting external A/V amp with built in Dolby digital and DTS decoders.

Ultimately they return to keep existing settings and 2.0 stereo output each time. have ensured everything is the latest version. Has anyone encountered this.

It does correctly apply the settings. It always shows "keep existing settings" after reload because it controls settings in multiple places that are not necessarily consistent.