Why this note?
Because I didn’t find one on the Internet addresses the gap issue.
See, the problem when you use the cloud backup you may not have enough cloud space. And more, between the moment you start the backup, until the backup is completed, you may receive several messages and medias. Which most likely will be lost once you switch to the next phone.
So, here we goes:
- Disconnect your Google drive from WhatsApp
Follow this article for the details: https://www.quora.com/If-I-have-both-a-Google-Drive-and-a-local-backup-of-WhatsApp-chats-how-do-I-ensure-WhatsApp-picks-up-the-local-version-to-restore-when-I-reinstall
- Get backup of WhatsApp folder to SD or Flash disk, and copy it to the new phone
- Install WhatsApp on new phone, and pay attention to the step after activation. If no backup is detected, or if it is trying to restore a cloud backup, then you missed something
Good luck 