Unwanted background bleeding through layer mask

Yes I've generally noticed that when you go over the same area it increases, but not in the case where I used the lasoo.  It just turns a muddy color, and stays that way.  I think the way to go is the select subject way where you have some control over capacity.   I don't know why Adobe doesn't put a slider in the refine edge menu when you use the lasso.  Thanks for the help.

@Dr_Bundolo said:

Is there a default setting that somehow got changed to grey? or a default opacity?

I'm not sure how that may have happened.  Although, if you had a non-default color setting for the color picker (e.g. a shade of red), when you switch to the mask brush, the color will change to a shade of grey.  When I work with a mask, I usually press D to make sure that the foreground color is set to white and I can then press X to toggle between white and black.

Thanks for taking the time.  Yes, I'm just trying to remove the girl.  I did use the remove subject EXACTLY as you did then refined edge, and that is what I got.  I'm wondering if you're on to something about the color in the mask. Is there a default setting that somehow got changed to grey?   or a default opacity?

OK.  It looks like you are using a grey color to paint on the white mask, instead of black.  This can happen if you lower the opacity of the brush to something like 50%.  See my following screenshot.

Using a black brush, I painted the left side at 100% opacity.  In the middle, I reduced the opacity to 50%.  On the right side, I turned it down to 0% opacity, which means that the black brush has no effect on the mask (leaving it white).

I'm not exactly sure what effect you are trying to create.  If all you want to do is remove the girl out of the background, there are perhaps easier ways to do that.  For example, here, I used your original (edited) image, opened the selection tool (Keyboard Shortcut A) and clicked on the Select Subject button. 

This does a pretty good job of selecting the girl, although you can modify the selection.  You can then use the Refine Edge button and modify the selection and output the selection to a new layer with a layer mask.

Hope this helps.

Can you post a screenshot of the layers panel.  (And cute photo.)