Goodmorning,
How did you transfer them?
Its best to start over, make 1 backup on the computer. Call the folder maybe backup and put all your whatsap images and videos in there.
Than on your phone delete everything. After this you copy the folder backup to your phone. This should solve your problem.
Its probably best to uninstall WhatsApp first and delete all the folders from your internal storage after you made the backup on the computer.
Than reinstall WhatsApp and copy the folder backup to your internal storage.