unable to use erase on mask layer for inpaint

[sould3mon]

whatever white has touched when drawing a mask stay's as a mask even after erasing.

to reproduce:
create mask layer
use white to create mask
remove some of white (with eraser)

https://imgur.com/a/EYEA8H0
hope this is clear (used black baground to show instead of origional image)

run inpaint
everything that white has touched is rendered

[Interpause]

Oh yeah, I ran into that too but forgot about it :p