Keith,
Based on your feedback, we verified a bug in the editor that must have come up with a recent publish. I have the web team looking into this and it marked as a critical issue that needs addressing asap. As it stands at the moment, disabling is not working as you noted. The “blinking” your getting is a result of the page reloading with no change due to the issue. It is not prompting the save option due to it not accepting the change for disabling. I will update this thread when we publish the fix for it.
Thanks,
Mike