I have a React Native chat app that connects to an XMPP server hosted on Azure.
The app is using websockets for the connection (ws:// not wss://) with the xmpp.js library.
The app can connect when run locally with a Debug build, but fails to connect when using a Release build.
The same app running on iOS connects with no problems locally or when deployed.
I've tried using the debug signing config for release and also creating a release config with a new keystore.
The solution was to allow all network connection types in AndroidManifest.xml
<application android:usesCleartextTraffic="true">
</application>
For more details, see the top answer from the following post:
How to allow all Network connection types HTTP and HTTPS in Android (9) Pie?