Highlighted portions of book got vanished

@dr.satyaprada ouch! Sorry to hear. The most common reason for this is that the document wasn't properly synced to the Adobe Cloud after you made your highlights. Your changes were likely saved only on your phone, and a glitch or a lack of internet connection prevented them from being uploaded to the cloud.

To try and fix this, please make sure you are logged into the same Adobe account you used when you made the highlights. Then, make sure you have a strong, stable internet connection. Open the document again and leave it open for a few minutes. This should give the app a chance to sync your saved highlights to the cloud, hopefully making them visible again on your device and any others. Unfortunately, if the sync never happened and the local file was somehow reset, those highlights might be lost.