WhatsApp Desktop App failing to establish a web-socket connection on macOS Mojave

Whenever I open the app I'm getting one of these messages:

Make sure your computer has an active internet connection

or

Nothing works! After I cleared the application data, cookies, and everything, I got the screen where WhatsApp is trying to generate the QR code, and it still does not work as well, it kept trying to generate one!

After Opening the developer tools cmd+option+i on almost every problem I'm facing; the console log contains multiple errors. This is one of them:

WebSocket connection to wss://dev-web.whatsapp.com/ws failed: HTTP Authentication failed; no valid credentials available

Even with the newest version, I downloaded yesterday, it's still not working.

It's a problem related to MacOs Mojave (IFF you have a good internet connection for real and everything is working fine).

Grant access to WhatsApp desktop app:

System Preferences -> Security & Privacy -> Privacy -> Full Disk Access

after you open the lock please add WhatsApp app to this list.