I tried recreating this by booting a virtual machine with Ubuntu 21.04 installed with a Kubuntu daily build from 2022-01-17 and I saw the grub boot menu and was able to boot Jammy.
** Changed in: casper (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1958120 Title: Failed to load live CD Installer Kubuntu Jammy To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1958120/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs