this is exactly true and its happening with my phone also. I tried to delete the WhatsApp and reinstalled it but still the problem remains.
But this problem is only with Whatsapp so cant understand that is it a WhatsApp issue or phone software issue.
Please check from you side .......
# dual whatsapp
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.
Why is it taking too much time to solve this issue by number one smart phone selling company in the world.
Even Chinese smart phone brands are able to solving their customer issues on time.