Samsung addressed the issue and fixed it via AOD app update. The latest update for the Always On Display app (v4.2.51.3) fixed the AOD cut off error on both Galaxy S10 and S10+. The update is now available for download on Galaxy App Store and Google Play store. How to update the AOD app to fix cut off issue

Open the Galaxy Store app on your phone Tap the Menu button on the top right corner of the screen Tap My page, and update your AOD app You can also go to Play Store to update your app

Along with the AOD cut off issue fix, Samsung fixed the AOD doesn’t show when using Clear View cover issue through this update. The update also includes general bug fixes. Since the introduction of Always On Display, Samsung has made several improvements and added many new features to this function. Always On Display (AOD) shows useful information that’s available at a glance, even if the phone’s display is off and without affecting the battery life a lot. [Source]