tpPLC Android app won't connect to device
I have a TP-Link TL-WPA4220 Powerline Wifi Extender in our garage (25m from the house) and am trying to use the tpPLC app on my Android smartphone to connect to the device so I can check the settings.
The issue is that the app says "No device found", yet I know the phone is connected to the extender by Wifi (only 30cm from the device).
Looking at the reviews of the tpPLC app on the Google Play store I see that lots of people are having the same issues, but there's no clue about how to fix it.
The reason I wanted to use the tpPLC app was to check the settings on the Extender, as it disconnects once or twice a day - but the router in the house is not disconnecting. I know this because I have a Nest camera on the garage and two on the house (connected to the main router), but it is only ever the one on the garage that disconnects. Therefore it must be due to the extender, not the main router and its internet connection.
Please help.
Thanks.