Mission window contains information of previously opened scenario.
Repro case (example):
1. Load Showcase Queen Elisabeth.
2. Load Northern Fury 1
3. Mission Window contains data from the Showcase QE. See figure below.

Workaround:
There is no workaround this time. The only way is to close completely CMO and restart.
What I was expecting:
Mission Window contains only information from the actual scenario.
Build: 1271.1