Linux Fedora 38 was released earlier this week and already we have upgraded three systems. So far so good, no issues with the inplace upgrades.
The command line sequence as root goes like this:

dnf upgrade –refresh
reboot
dnf install dnf-plugin-system-upgrade
dnf system-upgrade download –releasever=38
dnf system-upgrade reboot
dnf system-upgrade clean
dnf clean packages
dnf upgrade
Fedora 38 upgrade complete!
Each took less than 30 minutes.