Hi, Erwin, thanks for your reply.
However, I think you did not understand the problem.
The M3 lost a crew, therefore, due to the standard game mechanism of CMBB, it should stay buttoned throughout the game. However, it suddenly unbuttoned itself at some point. That was never experienced by me before. So I was trying to figure out what might have caused this. It is unlikely a programming bug, if it is a bug, it should have happened before ---- and to others as well, so some1 would have reported such problems long ago (considrering that CMBB is already 10 years old). And I personally played over 500 CMBB games, it should not happen so rarely if it is a programming bug.