Do Not Disturb Mode does not block Whatsapp calls

Why Do Not Disturb Mode does not block Whatsapp calls? Contacted Whatsapp and they said:

"Hi,

Thanks for your message.

Your iPhone’s Do Not Disturb settings can also affect WhatsApp voice or video calling. To help resolve any of the issues you’re experiencing, you’ll need to make sure your settings are enabled to use voice or video calling.

Make sure you:

Double check your Allow Calls From settings to ensure your WhatsApp contacts can call even if DND is turned on.

Have turned off Repeated Calls.

Haven't chosen Always set under Silence.

Note: Do Not Disturb silences voice calls, but video calls will still come through.

For more information about the Do Not Disturb feature, please visit the Apple website.

If you have any other questions or concerns, please feel free to contact us. We'll be happy to help!

Melanie

WhatsApp Support Team"

How come "Do Not Disturb silences voice calls, but video calls will still come through"?

Please help!