I also have a boot issue with full root encryption never prompting for the password, also on a Dell, see:
https://bugs.launchpad.net/ubuntu/+source/linux-lts-xenial/+bug/1628546
I also have a boot issue with full root encryption never prompting for the password, also on a Dell, see:
https:/ /bugs.launchpad .net/ubuntu/ +source/ linux-lts- xenial/ +bug/1628546