Form width not saved/displayed in the customizer UI

After setting the ‘form width’, under general customization, and saving the form. I then go back to edit the form and the ‘form width’ shows that it’s set to 100% when it’s actually set to the previous width (but who knows what it is…)

To explain the discovery process:
It was very confusing. I had set the form to some width at one time, and it was too narrow. I couldn’t remember even doing it and where the setting was. I finally found the setting and it showed 100% which totally didn’t make sense, until I started playing with the slider…