iPad overrideUserInterfaceStyle not working after backgrounding app

I have been having some trouble with the overrideUserInterfaceStyle lately in our app. On iPad after a user backgrounds the app, when a user tries to set the apps interface style all the childviewcontrollers stop changing.
Code Block
window?.overrideUserInterfaceStyle = userInterfaceStyle


Brute Force Method

Code Block            
window?.rootViewController?.children.forEach({ vc in
vc.overrideUserInterfaceStyle = userInterfaceStyle
})

If I brute force it they update but when they revert it to system settings(.unspecified), it doesn't match the system anymore.

It works fine until the user backgrounds the app. Has anyone else faced this problem?