OS: Windows 10
Clicking Start Listening is fine:

I can create a breakpoint on line 7 by double-clicking it:

And I can remove the said breakpoint by double-clicking it again, everything is fine:

Then, I create a breakpoint again on the same line, refresh the page, and pugdebug stops execution at the said breakpoint:

Great! Then, I click Run and the execution continues and the page loads fully, but the "breakpoint square" on line 7 is still red:

Then, I double click on the line 7 to remove that breakpoint, and here's what happens:

The breakpoint is seemingly removed, but also seemingly is not. I double-click that same line 7 again, and get this:

Double-clicking that line again goes back to this:

And the loop continues with no way to remove the breakpoint by double-clicking the line.
Thank you and all the best!