A team member shared a Google Form for me to fill out. Strangely that form URL could not open in Firefox. It would not load with this error:
The page isn’t redirecting properly An error occurred during a connection to docs.google.com. This problem can sometimes be caused by disabling or refusing to accept cookies.
I did not have any setting in Firefox to disable or refuse some cookies. So that error was wrong. But it gave a hint that the problem might be caused by cookies.
I went into the Firefox options and deleted all cookies involved with the URL google.com. There is no need to delete all cookies, just those that have this URL. Once I did that, the Google Form URL opened correctly.