For those that are trying to add another WeMo using your Android WeMo application; with the latest version of their app - it will NOT let you w/o creating a WeMo account which then converts your WeMo mgmt from local network to cloud based using their systems. This alone could be a problem with the WeMo OH binding since it doesn’t do any authentication within it.
I found their older version of their WeMo app which doesn’t force you to create an account and convert to their cloud based mgmt tied to a username/password.
You have to uninstall their latest WeMo app first and then install this version below.
https://www.apkmirror.com/apk/belkin/wemo/wemo-1-24-release/wemo-1-24-android-apk-download/download/
Best, Jay