You can check the reason for the failed messages on the failed logs section of the Whatsapp section. Click on the Whatsapp icon.
Step 1: Click on the Failed logs to directly check the logs for which the Whatsapp message failed.
Also, the alerts on the dashboard include the number of failed logs in the case of WhatsApp and will redirect to the failed logs section.
Step 2: If you want to see the content of the message in the case of failed logs, please click on the log and you can see its content as well.
Happy WhatsApping!!:)