Sophos  will actively block networking connections (even Ethernet) until the Sophos Shield  appears in the task bar (the bar on the top right of the screen).
 

If the Sophos Shield  does not load after a minute, follow these steps;
 

1. Launch Sophos  from your Applications Folder .
   
    
2. ​Go to Sophos Anti-Virus > Preferences.
   
    
3. Ensure On-Access Scanning is on
   
    

The Sophos Shield  should then appear on your task bar (top right side of screen), and your internet will then be able to connect properly.