Explaining Bindable Property Issue

Dear all

It looks like I do missunderstand something in bindable properties. I would appreciate if somebody could explain me, how to do it correctly and why it works like that.

Why does the Binding on the "MeetingControl for "Meeting.Subject" not work?

GitHub Link: [h]ttps://github.com/PatrickRainer/BindablePropertyExample

I would appreciate your feedback and advise.

(If somebody would like to teach me one to one, I am willing to pay a fee for that learning.)

Thank you
Patrick