ERR_CONNECTION_TIMED_OUT, also called the timeout error, means a website took too long to respond to the browser's request. Generally, a site can establish communication with a computer within 30 seconds. If it takes longer than that, the browsing application will terminate the connection.
What causes connection timeout?
Server timeout and error messages occur when a program attempts to connect to a non-existent server, either because it is down or because the IP is incorrect. As a result, your browser requests information that the server does not have.