thank you for your answer and sorry for the bad words I wrote yesterday. I did not want to criticize the whole team, I was only a little bit disappointed
You are right, that the file is not changed when having the app unlocked/locked. But I guess that it is possible to retrieve the passwords in plain-text when having it unlocked (e.g. a browser bug or other app's bugs). I agree with you that it is really unlikely, but I guess its a bit more secure when having it locked most of the time.
For me the version 7 feels a bit unstable (not only locking and unlocking). The support team already had a look in some logs ... the answer was that it's the way the app currently behaves. But as I said for me it feels a bit unstable because every action needs a few seconds.
If you have some ideas, please let me know. If needed I can provide some further system information.