WhatsApp media does not download completely.

[FeliApple]

I bought an iPhone 6s and I am trying to get the whatsapp chats to the new phone, from my 5s. Earlier today I uploaded a copy of everything to iCloud. Messages (No media) downloaded immediately, and then it prompted me to restore media. I accepted. Total size is 768 MB or so. It downloads in the background, so on top of the conversations a tab appears that says downloading media and a progress bar. Progresses seamlessly until it reaches 750 MB. There, it goes back to 11 MB and starts again. First time I said: Ok, must be a bug, let´s wait for it again. Second time, same thing happens.
I now proceed to redownload WhatsApp, and try again. Same thing happens, it is on a constant loop and no media is actually available to see.
Any ideas on what to do? Funny thing is I did not restore from a backup to avoid bugs, as I screwed up my iPad when restoring from a backup, and I still have bugs...
Edit: Backup size on iCloud is correct, at 800 and something MBs, and I had no problems whatsoever with creating the actual backup at first.

 

[FeliApple]

For the sake of people reading this in the future here's the update: I left it several times more, nothing. I always interfered when it finished once and restarted, I reset the phone, reinstalled the app, etc. Nothing. I woke up today at 6am and said ok, I'll turn Wi-Fi on and open the app. I did that and 4 hours later when I woke up it was at installing. It finished up on its own, probably starting again several times, up to now without errors.
If you encounter this, just leave it for several hours doing it's job and don't be anxious like me.