diff --git a/packages/react-devtools-extensions/src/background/dynamicallyInjectContentScripts.js b/packages/react-devtools-extensions/src/background/dynamicallyInjectContentScripts.js
index 4e8811fddb847..08db763bdbaa7 100644
--- a/packages/react-devtools-extensions/src/background/dynamicallyInjectContentScripts.js
+++ b/packages/react-devtools-extensions/src/background/dynamicallyInjectContentScripts.js
@@ -11,7 +11,7 @@ const contentScriptsToInject = IS_FIREFOX
         js: ['build/proxy.js'],
         matches: ['<all_urls>'],
         persistAcrossSessions: true,
-        runAt: 'document_idle',
+        runAt: 'document_end',
       },
     ]
   : [
@@ -43,26 +43,19 @@ const contentScriptsToInject = IS_FIREFOX
 
 async function dynamicallyInjectContentScripts() {
   try {
-    const alreadyRegisteredContentScripts =
-      await chrome.scripting.getRegisteredContentScripts();
-
-    const scriptsToInjectNow = contentScriptsToInject.filter(
-      scriptToInject =>
-        !alreadyRegisteredContentScripts.some(
-          registeredScript => registeredScript.id === scriptToInject.id,
-        ),
-    );
+    // Using this, instead of filtering registered scrips with `chrome.scripting.getRegisteredScripts`
+    // because of https://bugs.chromium.org/p/chromium/issues/detail?id=1393762
+    // This fixes registering proxy content script in incognito mode
+    await chrome.scripting.unregisterContentScripts();
 
-    if (scriptsToInjectNow.length) {
-      // equivalent logic for Firefox is in prepareInjection.js
-      // Manifest V3 method of injecting content script
-      // TODO(hoxyq): migrate Firefox to V3 manifests
-      // Note: the "world" option in registerContentScripts is only available in Chrome v102+
-      // It's critical since it allows us to directly run scripts on the "main" world on the page
-      // "document_start" allows it to run before the page's scripts
-      // so the hook can be detected by react reconciler
-      await chrome.scripting.registerContentScripts(scriptsToInjectNow);
-    }
+    // equivalent logic for Firefox is in prepareInjection.js
+    // Manifest V3 method of injecting content script
+    // TODO(hoxyq): migrate Firefox to V3 manifests
+    // Note: the "world" option in registerContentScripts is only available in Chrome v102+
+    // It's critical since it allows us to directly run scripts on the "main" world on the page
+    // "document_start" allows it to run before the page's scripts
+    // so the hook can be detected by react reconciler
+    await chrome.scripting.registerContentScripts(contentScriptsToInject);
   } catch (error) {
     console.error(error);
   }