ZBrushCentral

hide and show unmasked areas

I’ve used hidePt to hide unmasked areas and then show pt to show the areas again, however this only works a couple times then the hide will not hide unmasked area(s) again. Why is this happening?
I then tried the rectangle marquee to hide the area and most of it is hidden except where i started the marquee, there is a little of the rectangle showing. Tried many different ways with no success. I’m stumped.