WhatsApp Backup can't be downloaded?

So I switched from the Sony Z5 Premium to a Huawei P30 Pro with a new number. WhatsApp made backup, on the old phone into the WhatsApp pure, settings, change number, number changed. WhatsApp installed on the new, backup downloaded. Went so far, chats are all there. But since I did that at work, it wanted to wait for the media on Wi-Fi. Now I'm at home and get the following error message: Media could not be recovered due to problems with Google drive. Please try again later. Where is the mistake?

Wa now reinstall again and restore backup again