Since the installation of SP4, all Yealink W52P phones function as gateways - allowing to serve up to 5 handsets. We however had these phones already added and provisioned as normal - bound to extensions. Now, after the upgrade, adding the FXS/DECT doesn't work - we get a 'This Phone / MAC belongs to Extension ...'. If you go to the settings/Phone Provisioning of the extension in question, there is no Yealink phone to delete, just an Astra 51i/6751i with no Mac Address. And you can't delete it. How do I delete the Yealink from my extension to be able to add it as DECT?