I followed the approach mentioned by Caomhin
If you are using a Beta version of WhatsApp, backup your chats and try
Uninstalling WhatsApp and revert to an earlier Stable version.
Also while chats are backed up clear the WhatsApp App info Cache and
App info Storage as well.
Log back in and see if that can help.
In order to do the backups,
- Open WhatsApp
- More options
- Chat backup (without videos, or else it'd take too long in my case)
Then, uninstalled the app and left the Beta program.
After I installed the normal version, restored the backup and now it's working fine.