It looks like Apple is not fully modified this function.
Users of various models of the iPhone have complained that some apps on their smartphones are working properly. For example, in the official YouTube app when watching videos in full screen mode quite often shows a bug due to which the interface appears and disappears every second. As it turned out, the problem is not third-party apps, and new iOS 12.
Most often the bug manifests itself when watching videos in full-screen mode in various applications. Video starts playing in fullscreen mode, but the interface of the playback control appears and disappears on the screen like the user every second to the display of the smartphone.
The first such strange bugs in different applications users complained the iPhone 5s and iPhone SE. The complaints were received on YouTube, Instagram, Twitter and other popular applications you use every day. Subsequently, however, a problem in third-party applications, said the owners of other iPhone models.
One of the users decided to investigate the situation and empirically found out what the problem is. As it turned out, many third-party applications on the iPhone start to work weird because of the standard functions of the “Screen time”. It is assumed that the function continuously monitors the activity of applications that do not allow them to work normally.
Thus, to get rid of the iOS 12, you must disable the “Screen time”. This can be done in the menu “Settings” → “Screen time“. Note that disabling the feature will increase battery life of your iPhone.