Andyc55 wrote

Set up new H100 and can see all devices remotely.  Alarm/siren on H100 doesn't work and when I try to sound the Ringtone from the App I get the unstable connection message.  This device is sitting 20 feet from an AT&T FTTH modem.  2.5 and 5g bands are split onto separate SSIDs.

  @Andyc55 

Please make sure no VPN is enabled on your phone while using the Tapo app. Keep your Tapo app updated. You can try to delete and reinstall the app. 

Can you ring the hub when your phone is connected to the same WiFi network as the hub? Also, try controlling the hub with a different phone to see if the problem is specific to your main device.