su dnf update dnf upgrade --refresh - Ultimately nothing to do by either of the above dnf -y system-upgrade download --refresh --releasever=402997 packages to download. Indeed, no issues. And we have a bigger root partition due to the way I install F39.
dnf system-upgrade rebootType escape to see actual system messages in lieu of the cute graphical progress screen.
This all worked out in short order and I am now running Fedora 40, but ...
My mouse is slow as a pig -- I suspect my Nvidia driver setup got lost.
AHA!! So, I reboot after this, and I now have a system I can use and enjoy. I went through an issue like this with Fedora 38 also, and all I had to do was wait and install an updated akmod driver.
Adventures in Computing / tom@mmto.org