Image color selection UI (likely) bug
Super trivial but when you create one of these masks it sets softness to 20. One can see the UI thinks it is set to default. It is not. 30 is the default. So the normal Imerge "reset" feature cannot operate there.
Then this begs the question. Should the value be 20 or 30. I think 30. Lower values in this option seem to give splotchy results. 30 probably a better default and is the default for this effect and Color adjustment.