Stamp tool does not work properly in darktable 3.0

Stamp tool used to work reliably in previous versions of DT. In 3.0.s it is very flaky. See the attached screen shot. I drag the circle to a clean spot and released the mouse button, still spot has not gone. I clicked on some other module(other than stamp module) still no use.

Is there any workaround?

Since I use MILC, it is difficult to avoid dust and depend on stamp tool a lot.

Thanks
Ramesh

Can’t see much out of your screenshot, but I remember there were some issues because the opacity was not set to 100% by default.

Hover with the mouse above a circle, hold CTRL and move the mousewheel up.

Thanks pphoto.

I just figured out that opacity is problem. Please see the attached pic. Actual opacity and what is shown in slider does not match. Mostly it is my mistake, I might have pressed CTRL key and that reduced to actual opacity. I came to know about actual opacity being so low when I liked at text.

Regards,
Ramesh

There was a discussion about this issue some weeks ago. Look at the text overlay at the top of the image. Set feather size and opacity properly. You need an opacity of 100 %, as pphoto already said.
If opacity is at 100 percent and the issue remains, you can check the parameters manually. The parameters for the tools are stored in ~/.config/darktable/darktablerc (on linux). Quit darktable and edit the settings with a text editor (backup first !!!). Search for the discussion I mentioned ( darktable 3.0 masking inconsistencies & bugs ), there you will find further information.

Or use the retouch tool with the heal brush settings