When you log into MapBrowser, a new MapBrowser session will always open with the URL from the close of the last session, unless you use a specific URL to launch MapBrowser.
The URL contains all the location information of your current view. You can learn more about this here: About the MapBrowser URL.
So if you are concerned that your base layer is not defaulting to, say, Vertical, it's because when you lasted signed out you were viewing a different base layer.
You can always save a view by one of these three methods:
- bookmarking the URL
- sharing the URL
- creating a Project. The Project saves your last view characteristics also. Find out more here: Projects Tool