Try resetting the Healing brush (left end of Options bar). I also thought that the Healing brush worked best with a fully hard brush, which makes sense if you think about it, because it needs all the edge information to blend with the surrounding pixels. You are staving it of information with a soft brush.
Thank you, Trevor!
It looks like the change to a hard brush did the trick. I just need to "soften" the brush in a
few areas that are softer in focus or then it looks like a stamped area.
I still haven't solved the "disappearing" brush mystery. It's doing it right now.
Use the healing brush on an Empty layer with is set to Sample all layers in the Options bar. When finished, Ctrl (Cmd) click the new layer to load it as a selection, and add a Layer mask to the layer. You can now use the Mask properties panel to adjust the mask. Feather the mask for a softer transition, for instance.
Would you believe me when I tell you that I don't use layers?
I mean I have in the past if it's something that is going to print or for a client.
Currently, the images I'm working on is for my website. I have the final & original files
but when it comes to web images they (final image) ends up being smaller files.
Your suggestion of just changing the brush to harder worked.
I reset the brush presets and hopefully that will clear up the brush's disappearing trick.