Can't delete Pole in Edit Response

[metempleton]

When I try to delete a Pole element in Edit Response, the "deleted" element remains upon reopening the Editor.
I tried three approaches, with the same result:

1. Select 'Pole', click "-", Save
2. Select 'Pole', click "-", close Editor window
3. Delete child elements Real, Imaginary first (select, "-"), then delete 'Pole' and Save

[metempleton]

I had the same problem trying to delete a Zero