Hi @MikeG, welcome to TPG Community!
Do you notice if any of the WAN/DSL/Internet lights on the modem is flashing/off when the connection drops?
You can try the following troubleshooting, see if it helps:
1. Make sure the cables are connected securely
2. Use the supplied power adapter for the modem
3. Connect the modem directly to the power source
4. Do a factory reset on the modem (configure manually if required)
5. Check for wifi drop outs (Easy Steps to Improve Wi-Fi Connection In Your Home)
You can also send us a private message with your account details and we'd be happy to have a closer look at your connection.