One quirk with Roll20 and the browser environment in which it runs is that opening more than one game in the same browser will confuse things. You can refresh the first game and end up in the second, or whatever. If you ever need to access 2 games, you either need to have one in a regular browser session and the other in a private session/window, or you need to have them in separate browsers (one in Chrome, one in Firefox). Otherwise, you will get strange things happening like reloading and ending up in a different game that has been accessed in that session. If you exit a game session (not just close the tab) from the button in the settings tab in game, then you should be able to launch another one in the same browser session without problems.