Grass is persistent over dirt in chunks of my landscape but not others - how can I fix?

when i use the landscape painter to paint dirt, it clears the grass on top in one section but not the others. see photo. My island was a starter template that seems to be divided into sections. when the brush goes from one section to aother, it’s acting like there is some kind of mask that keeps the grass. Can anyone explain why this is happening and how to fix? thanks.

@RemindMeToBuild Thank you for your report! We would like to look into this further, would you be able to submit a bug report using the form available here? Fortnite Creative

I filled out a bug report, but after updating UEFN today, the issue is fixed for me. So maybe it was fixed in the latest release. I will report again if it happens again. thx