Xfinity stream app on Samsung TV

The Xfinity Stream app will load but not allow me to watch live TV.  It works on my iPad which is connected to the same home network,  I have rebooted the router, deleted and reinstalled the Xfinity stream app and confirmed that my wifi signal is strong and that there are no outages in the area.  All other streaming apps work fine (Netflix, Prime, etc).  This has been an intermittent ongoing problem but this morning we cannot watch any live channels.  Any suggestions?