If Mozilla Firefox is not connecting to the internet, there could be several reasons for this issue. Here are some troubleshooting steps to help you resolve the problem:

Check Internet Connection: Ensure that your internet connection is working properly. Test other browsers or applications to confirm if the issue is specific to Firefox or a broader internet connectivity problem.

Restart Firefox: Sometimes, restarting Firefox can resolve temporary glitches. Close the browser completely and reopen it to see if the issue persists.

Clear Cache and Cookies: Clearing the browser's cache and cookies can help resolve issues related to stored data. Go to Firefox Options > Privacy & Security > Cookies and Site Data > Clear Data.

Disable Extensions: Certain Firefox extensions may interfere with the browser's ability to connect to the internet. Try disabling extensions one by one to identify if any of them are causing the problem.

Thank you very much. This is a standard reply which is not applicable. This is some bug in Firefox update. Nothing has changed in my PC and firefox was working fine just before the update. Even now Chrome and edge are working fine.

Might check Tools -> Settings -> General and scroll down to the bottom and click the Settings button in the Network Settings section and set it to No Proxy if it is set to something else.

Also, you might check Tools -> Settings -> Privacy & Security and scroll down to the DNS over HTTPS section and set it to Off if it's set to something else.

I guess another thing to check is clicking the File menu and make sure Work Offline is not selected. I'm running the latest update on my PC and it's all working fine.

Just trying to think of things.