When doing anything that requires momentarily leaving browser focus, such as hopping to an authentication app or email or text to receive a 2 factor authentication code, the browser will refresh the current page every time I hop back to Firefox.

This usually causes in most cases the code I left to retrieve to become expired as it now wants a new one when the page refreshes. In most cases this also wipes out the entire content of forms that I have taken time filling in. This can happen any time the app loses focus, even if somebody just phones me and I don't even volunterily leave the app.