Sorry to add to an old issue, but I can confirm the issue persists under Ubuntu 18.04.5.
I can reliably reproduce the issue when installing 18.04.5 on physical hardware, Lenovo ThinkPad P15 (20SUS5LJ00). The error message after changing the passphrase in gnome-disks is: Error changing passphrase Error changing passphrase on device /dev/nvme1n1p3: Failed to add the new passphrase: Invalid argument (udisks-error-quark, 0) [Close] -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1837437 Title: disk content permanently lost when changing LUKS password To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libblockdev/+bug/1837437/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs