iOS - Onboarding设置导致JWPlayer fullScreen按钮加载初始视图控制器

I have a tab bar application (Swift 3, Xcode 8.3) with three tabs. When the app is first launched, the code checks UserDefaults to see if a user is logged in. If there is a user, the initial view controller (the first tab) is loaded. Otherwise, an onboarding screen is loaded for the user to log in, after which he/she will get to the first tab.I have a tab bar application (Swift 3, Xcode 8.