You may see "Grammarly couldn't establish a connection to the server" when working in the Grammarly Editor:
To resolve this, we recommend refreshing your browser's page and reconnecting to the internet.
Note: Antivirus, firewall, VPN, and network proxy settings can cause the issue. Please try to resolve it by temporarily turning them off. If that helps, we suggest that you add Grammarly to that software's allowed list to resolve the issue.