Why is the Speech focus slider disabled for me in the myPhonak app?

I use a single hearing aid. When attempting to adjust the settings in the "Speech in Loud Noise" program, the Speech Focus slider is disabled.

This feature is inactive for users with only one hearing aid because it relies on StereoZoom and StereoZoom 2.0 technology, which require a binaural fitting (two hearing aids) to function properly.