Exclude Region - Unable to delete created exclusion area

Hi, I am new to 3D printing and OctoPi. I have a small failed area, so wanted to exclude it. I didn't think it through, but realised before continuing that I should delete the exclusion.

It doesn't appear that I am able to. There is no delete button. I tried to move the exclusion to another area, but it won't let me move it either, I can only make it bigger.

Any help would be most appreciated