I'm using Firefox 79 and since some update month ago I get the basic auth password prompt each time when opening the developer tools. This happens on a password protected staging site.
The curious thing is I logged in before and an auth cookie is set so I can browse the site after that. When opening the developer tools the password prompt shows up again. When I close it and hit refresh I'm still logged in.
When inspecting the server log it shows another GET request is made to the current page in the moment opening the developer tools. But it seems the auth cookie is not sent in this one request (401 Unauthorized). Navigating the site with dev tools open after this automatic request then works without logging in again.
I wonder why this automatic request is happening and/or why the auth cookie isn't sent here?