Hi! Just to add my experience on this topic.
It happens "some times" also to time. The a/c gets "partially/wrongly" loaded by MSFS sometimes with all lights on and some onboard systems out of working. It should be strictly related with the MSFS bug of the "not well loaded aircrafts" which happens randomically at the start of a new flight...it styarted to do so from such MSFS release this spring.
To "mitigate" it, its funny, but to me works: when I load the a/c I make sure to wait until the a/c view from the front door appears in the slideshows of the flight loading, on such moment I start the flight and no more issues.
Instead if I "start the flight" immediately when the sim button appears, I can "often" encounter such sim issue.