Assuming this is on iOS, are you saying it disappears at the top level of the app, or as you start to view articles in collections?
If it's the former, I have not observed this behavior. Could you post a screenshot plus some potential steps you may have taken to create the issue?
If it's the latter, that's expected. As the user starts viewing articles from a browse page the app doesn't show the menu icon, just a chevron button to allow the user to go back. We've heard in forums about this and we are evaluating our designs to improve the nav experience and allow access to the menu at lower levels of the app.
