React Native Metro over HTTPS (Android device, RN 0.74) still tries HTTP

I’m working on a React Native 0.74 app with a third-party SDK that requires Metro to run over HTTPS instead of HTTP. I prefer to use USB method over WI-FI.

Setup

• React Native 0.74.1

• Android physical device (Samsung Galaxy A22 5G)

• Developing on macOS (Metro running on my machine)

• Using mkcert to generate certs with SAN = localhost, 127.0.0.1, ::1,and my LAN IP

• Installed mkcert root CA on the Android device as a CA certificate

• Added a debug network_security_config.xml that allows <certificates src="user"/>

• I can verify from my Mac:

curl -vk https://localhost:8081/status   # workscurl -v  http://localhost:8081/status    # fail

What I’ve tried

1. Metro HTTPS config

metro.config.js:

server: {  secureServerOptions: {    key: fs.readFileSync('./certs/key.pem'),    cert: fs.readFileSync('./certs/cert.pem'),  },},

and starting Metro with:

npx react-native start --https --port 8081 \  --key ./certs/key.pem --cert ./certs/cert.pem --reset-cache

2. USB + adb reverse

adb reverse tcp:8081 tcp:8081

and setting Debug server host & port for device on the device in Dev Menu →localhost:8081. Have also tried the setup with another port ex. localhost:9091. And if I write https://localhost:8081 it just gets prepend to http://https://localhost:8081.

3. Wi-Fi

Set Debug server host & port for device→my_ip:8081.

4. SharedPreferences override

Tried pushing this file intoshared_prefs/ReactNativeDevPrefs.xml and com.facebook.react.packager_preferences.xml:

<map><string name="debug_http_host">localhost:8081</string><boolean name="dev_server_https" value="true" /></map>

I also added equivalent code in MainApplication.kt (onCreate) to write these values on startup.

5. mkcert CA on device

• Confirmed it’s installed as a CA certificate and
• My cert includes the LAN IP + localhost + 127.0.0.1.

The problem

Despite all this, the app still tries to connect withhttp://…instead ofhttps://.

On red error screens "Could not connect to development server.." I see:

URL: http://localhost:8081/index.bundle?platform=android...

instead of

URL: https://localhost:8081/index.bundle?platform=android...

Even with prefs set to dev_server_https=true, it seems React Native 0.74 keeps falling back to HTTP.

Question

• How can I force React Native 0.74 to use HTTPS for the dev server?

• Is there a reliable way to ensure Metro only listens on HTTPS (no HTTP fallback)?

• Is there a known limitation in RN 0.74 around HTTPS dev servers?

Any working examples (preferable USB or else Wi-Fi) would be hugely appreciated 🙏