App crashes in background while changing permission - swift

I need to prompt users to change camera permissions for my app via a UIAlertController. The alert has the following action:

alert.addAction(UIAlertAction(title: "Open Settings", style: .default, handler: { (action) -> Void in

    guard let settingsUrl = URL(string: UIApplicationOpenSettingsURLString) else {
        return
    }

    if UIApplication.shared.canOpenURL(settingsUrl) {
        DispatchQueue.main.async(execute: {
            UIApplication.shared.openURL(settingsUrl)
        })
    }
}))

This does work in so far as it opens the settings, but if the user changes the Camera permission, the app crashes in the background with Message from debugger: Terminated due to signal 9.

They can now open up the app and the permission is correct, but they need to start from the beginning. Does anyone know how to solve this?