Don't worry, it's actually very simple

When Google Chrome thinks that your network has changed, the browser will start showing a "Network change detected" error message. Normally, the error message should go away on its own. However, if it doesn't, there are a few things you should try to fix the problem.

There are several ways to fix Chrome’s network error and get the browser back to normal. Try each of the following methods and your problem will likely be solved.

When you see the "Network change detected" error, the first thing you should try is refreshing your current web page. This will force Chrome to re-establish a connection to your site, which will usually fix the issue.