Rahul on our android app we use a custom User Agent (our Foodomaa user agent)
This is causing the 3rd party chat platforms like Tawkto, Zopim etc to malfunction.
The Foodomaa user agent cannot be changed as all the native android features are built around it.
We will try to find a solution later.
For now, you can add custom html with your support WhatsApp number like: wa.me/123456789
This will trigger the WhatsApp chat directly.