Why does mask sometimes cover whole image when using combined drawn & parametric masks ?

If you want your resulting mask to be those areas/pixels which are both in the drawn mask and in the parametric mask, then it should work, but as above, do the para mask first. (And first reset the module in case it’s remembering anything from your previous attempts)

If you want anything else then good luck!, it’s quite difficult or impossible. There’s a bug report about the “inclusive” setting here

and I’ve proposed a revamp of the interface here