[MOO-2172]: fix open dev tools visibility issue

android/app/src/production/java/com/mendix/developerapp/MainApplication.kt

@@ -1,6 +1,8 @@
 package com.mendix.developerapp
 
 import com.facebook.react.devsupport.interfaces.DevBundleDownloadListener
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
+import com.facebook.react.internal.featureflags.ReactNativeNewArchitectureFeatureFlagsDefaults
 import com.mendix.developerapp.loading.BundleDownloadListenerHolder
 import com.mendix.developerapp.sampelapps.SampleAppsManager
 import com.mendix.developerapp.splashscreen.SplashScreenPresenter
@@ -18,6 +20,31 @@ class MainApplication : BaseApplication() {
         var splashImagePath = splashBackground(backgroundImage)
     }
 
+    override fun onCreate() {
+        // MendixReactApplication.onCreate() runs SoLoader.init() and then
+        // DefaultNewArchitectureEntryPoint.load(), which itself calls
+        // ReactNativeFeatureFlags.override(...) exactly once. So by the time we
+        // return from super.onCreate() the native lib is loaded AND the flags have
+        // already been overridden once.
+        super.onCreate()
+
+        // Enable the React Native DevTools (Fusebox) CDP backend in release builds.
+        // In release, InspectorFlags reads ReactNativeFeatureFlags.fuseboxEnabledRelease()
+        // (defaults to false), which bakes a "legacy" vs "fusebox" inspector target id into
+        // the device registration. Without this, the dev menu's "Open DevTools" registers as
+        // a legacy target and Metro's /open-debugger can't find a fusebox target to open
+        // (silent no-op). We use dangerouslyForceOverride (not override) because the flags
+        // were already overridden by load(); a second override() would throw. This must run
+        // before the inspector first reads the flag (i.e. before connecting to the packager),
+        // which onCreate satisfies. We extend the New Architecture defaults so bridgeless /
+        // Fabric / TurboModules stay enabled.
+        ReactNativeFeatureFlags.dangerouslyForceOverride(
+            object : ReactNativeNewArchitectureFeatureFlagsDefaults() {
+                override fun fuseboxEnabledRelease(): Boolean = true
+            }
+        )
+    }
+
     val bundleDownloadListenerHolder = BundleDownloadListenerHolder()
 
     override val devBundleDownloadListener: DevBundleDownloadListener

android/app/src/production/java/com/mendix/developerapp/mendixapp/MendixProjectFragmentBase.kt

@@ -25,6 +25,11 @@ open class MendixProjectFragmentBase : MendixBaseFragment() {
 
         viewModel.status.observe(viewLifecycleOwner) {
             if (it === ProjectLoaderViewModel.STATUS_SUCCESS) {
+                // Surface RN's "Open DevTools" item in the dev menu. isDeviceDebugEnabled
+                // defaults to ReactBuildConfig.DEBUG (false in release) and is in-memory only,
+                // so it must be set each launch once the React instance (and thus the
+                // DevSupportManager) exists. Safely no-ops when dev support is off (devSettings null).
+                currentDevSupportManager?.devSettings?.isDeviceDebugEnabled = true
                 RNBootSplash.init(requireActivity(), R.style.BootTheme)
             }else{
                 RNBootSplash.hide(requireActivity());