Encrypted disk will not shut down correctly

Recently, when I attempt to shut down my Dell Latitude E6530 with 16.04 encrypted on a 256GB SSD, the system will not shut down when requested. Rather the following occurrs:

1. Shutdown is requested
2. As the system shutdown proceeds with the screen black, error messages are flashed
3. POST begins
4. GRUB launches
5. When Ubuntu is selected from GRUB, sda5_crypt is challenged
6. The 16.04 Login is raised
7. The system halts with the user loigged in

That might be OK. But when the system is restarted, the system does not POST into GRUB. Rather, it POSTS directly into the 16.04 Unity GUI as the logged in user!

This is all making me very uneasy. First, I encrypted the disk for a reason - to protect data. Although the restart does still ask for sda5_crypt credentials, the GUI login is bypassed, so security is really compromised.

/Jay