ubuntu studio 22.04 lts to 24.04 lts upgrade

[Brian]

This upgrade has failed several times recently. After verifying 
prompt=lts in /etc/update-manager/release-upgrades, I just tried a 
do-release-upgrade -d and saw the following.

An unresolvable problem occurred while calculating the upgrade.

This was caused by:

* Upgrading to a pre-release version of Ubuntu.

24.04 LTS is up to a .1 now; has that been changed or held back?

Brian