Personal Observation/Comments:
Are you running 1.15.7.0 France/Benelux update?
If so, the following in the Patch Notes may apply:
KNOWN ISSUE
- The cockpit screens can end up in an unresponsive state if the RTC finishes and proceed into flight. Please make sure to click the Fly Now button before the RTC ends. (RTC = Real-Time Cinematic)