 Hi @philipz , I had not tested recovery key option (was a mistake when I think about it) but did so now after reading messages. I confirm the bug. (re @philipz: @saivinob did you notice this zfs bug that ubuntu-tester84d is mentioning)
 Here's what I did (I used Xubuntu iso). 1) Install with lvm+encryption option. 2) Note down the recovery key. 3) At next boot, use recovery key instead of passphrase that we set. 4) The key unlocks the disk and we are able to login.5) Once logged in, used 'luksChangekey' option to change the recovery key. Reboot.6) Use the new (changed) recovery key. Key unlocks and able to boot into system.Redid the test but now with ZF

  (edited)Here's what I did (I used Xubuntu iso). 1) Install with lvm+encryption option. 2) Note down the recovery key. 3) At next boot, use recovery key instead of passphrase that we set. 4) The key unlocks the disk and we are able to login.5) Once logged in, used 'luksChangekey' option to change the recovery key. Reboot.6) Use the new (changed) recovery key. Key unlocks and able to boot into system.Redid the test but no
 Passphrase works @Leokolb. Issue is with recovery key, on ZFS+encryption only. Recovery key on LVM+encryption is OK. (re @Leokolb: At reboot try entering the passphrase)
 tks (re @saivinob: Passphrase works @Leokolb. Issue is with recovery key, on ZFS+encryption only. Recovery key on LVM+encryption is OK.)
 Sorry - I misunderstood the original bug report - and can confirm your findings - thanks again- (re @saivinob: Passphrase works @Leokolb. Issue is with recovery key, on ZFS+encryption only. Recovery key on LVM+encryption is OK.)
 No issues at all @Leokolb 😀 And thank *you* for the confirmation.
 np (re @saivinob: No issues at all @Leokolb 😀 And thank *you* for the confirmation.)