Hi everybody, bit of a warning here: The recovery key generated during the installation of Ubuntu 23.10 (if you select tpm-backed fde) cannot be used to unlock the disk outside of boot, as in any 'cryptsetup' command and so on will not accept the recovery key. unlocking when accessed from different system does not work etc.
You can use it to unlock the disk while booting if your tpm somehow fails, but ONLY in that specific situation.
I kind of purposefully broke my tpm keys to see if it could be restored with 23.10 and ended up having to reinstal, as I ended up having to enter the recovery key at boot every time and no way of adding additional unlock options to the volume, as cryptsetup would not accept the recovery key as passphrase.
This bug could be very bad for new users.
See this bug report: https://bugs.launchpad.net/ubuntu-desktop-installer/+bug/2039741
I wasn't blaming cryptsetup, my mistake if it came across as though I did.
Thank you for taking the time to look into a possible fix, I might just reinstall with tpm-backed fde again to see if this really works.