4b67366 created the issue

If I have a bucket ACL set -- such as group "everyone" with permission "READ" and I use the dropdown to change "READ" to "WRITE" it does not appear that anything happens. If I delete the line with "everyone" with permission "READ" and then add a new line with "everyone" with permission "WRITE" it then resets the permission.

If using the dropdown will not have any impact once a permission is first set, there should be some indication of this.