Hello IBREC,
What you were seeing in 4.12.5 was actually a bug, and the way it behaves in 4.13.1 is the expected outcome. The unlit viewmode should not contain any sort of lighting or shadow information.
If you go to our 4.13 Release Notes you can find a bug fix that states: Fixed an issue where SSAO was being applied in the Unlit viewmode.
Let me know if you have further questions.
Thank you,