Help with using a black mask

[tombraider23]

I'm new to Substance Painter, and am using a black mask to put a texture in certain places on my sculpt. Instead of a clean stroke, it looks like I'm carving a chunk out of layer of paint. When I switch to a white mask, I'm definitely putting on layers of paint, which may explain what's happening with the black mask (e.g., digging into a layer of paint). I just want the center part of the stroke without the chunky paint around the edge.

How do I get rid of the chunk at the perimeter of the reveal? I attached a pic below. Thanks in advance.

[tombraider23]

When I save, close, and reopen my file, the mask doesn't even work! I can't paint away anything. Is this a bug?

[tombraider23]

Figured it out! The height position property on the layer was set too low. I kept it at .5, and it got rid of the issue.