The issue caused in Dual WhatsApp as recently WhatsApp upgraded its version and it changed the file path where all media files are to be saved. Due to this change, Dual Messenger didn't sync media saved at new path and so this is causing problem. Samsung is trying to solve the problem quickly by contacting WhatsApp team.
Samsung you sayed this befor 4 months any new or still trying to solve the problem quickly?
Settings>apps>(3 Dots on top right)show system apps>dual messenger>clear cache>restart device.
Or Settings > Apps > 3 dots in top right > Show system apps > Find and select the app > Storage > Select 'Clear Cache' and 'Clear Data'.
Or you need to restart the phone by holding the Power and Volume Down buttons (7-10 seconds) until the phone restarts.
This should solve your issue, if not please send feedback to our engineer's by using get help section: Get Help>>Send Feedback>>Erro rReport/Ask Question>choose appropriate section.
Please note that the issue caused in Dual Whats-app as recently Whats-app upgraded its version and it changed the file path where all media files are to be saved. Due to this change, Dual Messenger did not sync media saved at new path and so this is causing problem. Dual IM media sync logic is modified as per the new file path used by Whats-app. Please backup your files before device MR update (Whats-app`backup : Whats-app settings -> chats -> chat backup -> google drive).
For assistance, please visit one of our authorized Service Centers to check it for you. You may refer to the link it will guide you to the nearest service center to your location https://www.samsung.com/ae/support/service-center/
