To determine the cause of an internet issue in a specific room in your house, there are several steps that should be taken:

1. Check that all cables are connected securely


2. Try connecting to another device in the same room


3. Check if the internet is working on other devices in other rooms of the house and see what specific device or room is not working


4. If the issue lies within specific software, make sure to check the settings and firewall options


5. Restart the main router and check if any of the settings have changed


6. Test the speed of the connection by finishing a speed test online