Mixer Brush tool not selecting skin

I am trying to figure out how to reset the mixer brush tool at this point. I went into photoshop to smooth some skin on portraits and the mixer brush won't select the skin but instead has this weird static or automatically adjusts to solid color.  I can turn off the "solid color" option but it still just looks like static when I'm selecting skin and when I try to use the tool it just looks like a flat color instead of the texture of the skin. Anyone have this issue and figure it out?