WhatsApp history restoration on iPhone 8 Plus.

Recently I have just upgraded from iPhone 6 to iPhone 8+. Thus, I ran a restoration of my WhatsApp history on my iPhone 8+.

The only thing recovered was the chat history. The media(s) were in some kind of problems.

I can see the numbers and the little thumbail of the media in the chat, but it cannot be displayed. It was just blank. (See attachments)

I hope any of you guys can help me solve this problem. Thank you.