I want to provide the MAC address with my brand-new network extender, since other posts suggest that is why I'm getting the 5a error message. However, the extender doesn't show up as a "device" under my account, so I'm unable to proceed with phone or chat support. When I finally got the AI assistant to accept my request for a "live agent"... many, many minutes went by. Is there an email address I can submit this issue to?