Hi friend!
This is happening to me working with APP INVENTOR. Many times, when I finish working with my project, I save (several times) and even generate the.apk, when I work on it again, the last changes are not saved. It has even happened to me that I have the apk with a bug fixed, but in the project this fix was not saved. This happens to me many times. I ALWAYS press save project and lately I logout, but it keeps happening to me. How do you store your projects correctly? Does it happen to you?