LTS Upgrades (22.04 to 24.04) ARE BACK!
Quoting: LTS Upgrades (22.04 to 24.04) ARE BACK! – Ubuntu Studio —
Following a bug in ubuntu-release-upgrader which was causing Ubuntu Studio 22.04 LTS to fail to upgrade to 24.04 LTS, we are pleased to announce that this bug has been fixed, and upgrades now work.
As of this writing, this update is being propagated to the various Ubuntu mirrors throughout the world. The version of ubuntu-release-upgrader needed is 24.04.26 or higher, and is automatically pulled from the 24.04 repositories upon upgrade.