Hi Vincent, sorry to hear you are not able to get your data back as you want it. I don't know what method you use.
Open WhatsApp. Tap More options > Settings > Chats > Chat backup > Back up to Google Drive. Select a backup frequency other than Never. Select the Google account you'd like to back up your chat history to.
If this does not work you can check other third part tools like drfone, android recovery or Mobiletrans. They all vary depending on their capabilities.