Comment # 61 on bug 1228863 from Guillermo Perez

Got the same problem, booting after update always prompts for recovery key.
Previously, the machine always booted in default mode without any problems.
Aeon is installed on a SSD and there aren't any other disks with boot
partitions, I have a HDD formatted in NTFS from an old windows installation but
it was always used as mass storage and got no traces of any OS installation on
it. There wasn't any recent hardware nor UEFI changes.

Tried the following solutions:
1) reverting to various snapshots, without any luck
2) Running # sdbootutil --ask-pin update-predictions
3)Following the instructions on comment 56, which got me the following results:

Ran # rm -fr /var/lib/pcrlock.d . File gets removed. Tried to update and got
the following error:

~> sdbootutil -v --ask-pin update-predictions
Error: Can't determine root subvolume

After that, tried # systemd-cryptenroll to see if the PC could boot in default
mode and got:

No device specified, defaulting to '/dev/nvme0n1p2'.
SLOT TYPE    
   1 tpm2
   2 recovery

But the fact that can't determine root subvolume and there's not a device, I'm
afraid after rebooting, instead of getting the recovery key prompt, I simply
will be unable to boot.

So, as a summary:

* I'm getting asked for a recovery key after an update.
* None of the provided solutions ITT seems to work, and
* I may have made it worse and I don't know why.