Sophos SafeGuard Disk Encryption (SDE): SDE encryption progress screen displayed when computer is unlocked

Issue
After installing SDE on your computer, you lock the computer (or Windows does it automatically after you've been away for a specified amount of time). When you enter your password into the Windows logon screen, you return to the SDE encryption progress screen.

Sophos product and version
Sophos SafeGuard Disk Encryption