I'm trying to use the freehand mask tool in Add mode to "smooth" a mask edge. Instead I get a considerable expansion of the mask near where the freehand addition was done. Below are 2 screenshots, the first showing the tool as a triangle, the second showing the resulting mask just after a double-click of the tool. The freehand mask tool used to work very well and exactly but no longer does.
I have found the same thing occurs whenever I use the free-hand mask tool, even without smoothing. I have resorted to "guesstimating" where the marquee is going to land. I will sometimes use the "Paint On Mask" function to refine the messy parts of the mask.
Working at 250% zoom I'm not seeing this issue with PP 2018 or 2019
It is an issue with Photo-Paint 2017.