Hi @marco1, we recommend having a read of these community articles, which can help you with this query:
Wi-Fi troubleshooting steps - No Internet/Connection
Wireless Channel on your modem - what is it and why should I change it?
Should you require further assistance, please DM us your TPG customer ID, username and address so we can pull up the account.
To send a PM, please refer to this link: How do I private message (PM) in the community - TPG Community