It appears that there are 2 controls for the intensity of the HDRI lightening (Skylight).
If I access Intensity in the detail controls thru the “pencil” and change its value, the change is not reflected in the “main” window.
Conversely, a change of the Main intensity value will be reflected in the detailed controls.
This is a display glitch. It’s because the main display doesn’t ‘know’ it has to update as a result of the ‘pencil’ edit. It’s an oversight which I am correcting now. The fix will be in the next 6.0 update.