By the way, PureOS has the same bug, so I think it goes all the way up to Debian. Here's a guide I created on how to move a unencrypted install to fully encrypted (works with Ubuntu as well):
https://github.com/jjakob/wiki/wiki/Migrating-an-unencrypted-PureOS-Debian-install-to-fully-encrypted
By the way, PureOS has the same bug, so I think it goes all the way up to Debian.
Here's a guide I created on how to move a unencrypted install to fully encrypted (works with Ubuntu as well):
https:/ /github. com/jjakob/ wiki/wiki/ Migrating- an-unencrypted- PureOS- Debian- install- to-fully- encrypted