Can't isolate background

[PerVindis]

My problem is: I have a bird that I would like to isolate from the
background. I use Select Subject and LrC has selected too much which I
would like to remove. I use Subtract with Brush. Now I want Invert to
work with the background, but it's not the whole background that comes
up. - only the areas I have brushed. How can I select and work with
the entire background after the bird has been isolated?

[JohanElzenga]

What you need to do is select the subject mask and click 'Invert'. Then select the brush mask and do not invert it too, but click on the three dots. Change 'Subtract' to 'Add' and vice versa.

[PerVindis]

Tks a lot....