Firefox not loading node-red web UI on LAN

Firefox browser just presented me with a blank page.
So I have just wasted two hrs of my life, restoring a RPI image and copying nodes. After the restored from backup and problem was still there it was then I discovered Edge works fine!

Welcome to the forum.
Is the problem viewing the editor or dashboard or both?
Are Firefox and Edge running on the same computer? If so, after opening it in Edge does it still not open in Firefox?
What OS are you running on?
Did firefox work after reinstalling the Pi but with an empty flow?