Siril Mac - GHS bug or user error

Software Siril
1

Using any recent version of Siril with GHS on Mac, I’ve noticed that on repeated use of GHS, the stretching “mode” inverts itself. Not sure if it’s a bug or something I’m doing wrong. What I do is open GHS, select an area of my image and click the eyedropper to load the value into GHS. Then I use the “Stretch Factor” slider to stretch the image. When I’m satisfied with that stretch, I click “Apply”. So far, so good.

Then I select a new area of the image and repeat the same steps. Eyedropper, then slider. Now the image gets darker and the curve of the stretch is downward.

If I repeat the process again, the stretch returns to “upward” curve and brighter image, and if I repeat it again, again it gets darker.

The whole time, I have NOT changed the type of stretch to “inverted”. This remains on the “Generalised hyperbolic transform” setting.

Can anyone help?

2

Using this tool regularly, I’ve never found any abnormal behavior.
Depending on where the eyedropper is placed, it may give the impression of going backwards, but this is not the case.

3

So you’re saying its normal for the image to darken and the histogram curve to bend downwards when I increase the “stretch factor” slider, when the stretch type is NOT set to any of the “inverted” modes?