@MatthieuSG
Hi
1. Please check and ensure the internet line or ISP modem is stable, bypassing the TP-Link router. Connect the PC directly to the ISP modem (or internet cable from the wall), test and monitor the internet connectivity, and ensure you have a stable connection.
2. Login to the router web interface when there is no internet, and check if there is still a WAN IP address on the Status page. If yes, go to Advanced > Network > Internet, change the primary DNS to 8.8.4.4, secondary DNS to 8.8.4.4, then Save and reboot the router to confirm:
How to change DNS
If the disconnect issue persists after checking all the above, it is suggested to comment below and be sure to provide the following information:
1. Who is your internet service provider? What's the model of the modem?
2. What is the light status when issue happens?
3. How to recover the connection? By rebooting?