For customers experiencing any issues with their ADSL/NBN service, we recommend the best thing to do first is check if there's an outage on the ADSL/NBN network.
If there are no known outages in your area, customers can proceed with the troubleshooting steps indicated on this link : https://www.tpg.com.au/support/troubleshooting.php and https://www.tpg.com.au/support/nbn/troubleshooting_nbn_hfc
In your case, you've raised an issue with your REAL TV with our Tech team and it appears to be a third party issue as your service has been working fine with other devices. Our Tech team advised you to check with the manufacturer for a firmware update.
If your REAL TV box connects via WiFi, you need to make sure that you are getting around 80% and above signal strength. If not, then you need to move the device nearer your modem/router or check for a range extender or Mesh system to boost your WiFi connection.
Feel free to search Community for help with your issue, or contact us and we'd be glad to assist you.