Thanks Mac opt->preferences->display setting "New Line with Part Marker" solved the problem. It just should be disabled by default.

I tested it and it is global setting. So I do not have to change it in every BIAB session.

For example Notation Options "Minimize Rests" is annoying, because it is set to default value of "on" in every new BIAB session. BIAB does not save "Minimize Rests" to it's properties.

Thank you for your time!

B