After removing a filter list, only the cancel button is clickable however it doesn't actually revert the changes

If you remove a filter list by pressing the minus button, the done button remains un-clickable, only the cancel button is clickable. However, the cancel button doesn't revert the change.

The cancel button should re-add the filter list and there should be a done button for keeping the changes

Version 0.99.128.2.1.2-rc (WebKit 621.1.2.111.4)

Sequoia (15)