diff --git a/extension/js/common/platform/catch.ts b/extension/js/common/platform/catch.ts
index 79496a4f775..77ed6dffba9 100644
--- a/extension/js/common/platform/catch.ts
+++ b/extension/js/common/platform/catch.ts
@@ -174,7 +174,7 @@ export class Catch {
 
   public static environment(url = location.href): string {
     const browserName = Catch.browser().name;
-    const origin = new URL(location.href).origin;
+    const origin = new URL(url).origin;
     let env = 'unknown';
     if (url.includes('bnjglocicd')) {
       env = 'ex:prod';
@@ -262,12 +262,14 @@ export class Catch {
       }
     }
     const exception = Catch.formExceptionFromThrown(thrown);
+    const reportUrl = location.href.split('?')[0];
     return {
       name: exception.name.substring(0, 50),
       message: Catch.groupSimilarReports(exception.message.substring(0, 200)),
-      // Use https://mail.google.com/mail as URL for content script errors
+      // Strip Gmail URLs to group similar errors from different threads/messages
       // https://github.com/FlowCrypt/flowcrypt-browser/issues/6031
-      url: Catch.RUNTIME_ENVIRONMENT === 'ex:s:gmail' ? 'https://mail.google.com/mail' : Catch.groupSimilarReports(location.href.split('?')[0]),
+      // https://github.com/FlowCrypt/flowcrypt-browser/issues/6128
+      url: Catch.RUNTIME_ENVIRONMENT.endsWith(':ex:s:gmail') ? 'https://mail.google.com/mail/' : Catch.groupSimilarReports(reportUrl),
       line: line || 1,
       col: col || 1,
       trace: Catch.groupSimilarReports(exception.stack || ''),
diff --git a/test/source/tests/browser-unit-tests/unit-Catch.js b/test/source/tests/browser-unit-tests/unit-Catch.js
index 888a8d187cb..b3223022f98 100644
--- a/test/source/tests/browser-unit-tests/unit-Catch.js
+++ b/test/source/tests/browser-unit-tests/unit-Catch.js
@@ -70,3 +70,34 @@ BROWSER_UNIT_TEST_NAME(`Catcher does not include query string on report`);
   }
   return 'pass';
 })();
+
+BROWSER_UNIT_TEST_NAME(`Catcher reports correct URL for Gmail environment`);
+(async () => {
+  const originalEnv = Catch.RUNTIME_ENVIRONMENT;
+
+  // https://github.com/FlowCrypt/flowcrypt-browser/issues/6128
+  const sensitivePaths = [
+    '/mail/u/0/#inbox/WhctKLbvMNLndrHSj',
+    '/mail/u/0/#sent/KtbxLzFrMS',
+    '/mail/u/1/#inbox/rtjXfHsNNgrJVZL',
+    '/mail/u/1/#search/MSCGwzQrb',
+  ];
+
+  try {
+    for (const path of sensitivePaths) {
+      const fullUrl = 'https://mail.google.com' + path;
+
+      // Simulate environment detection based on the URL
+      const env = Catch.environment(fullUrl);
+      Catch.RUNTIME_ENVIRONMENT = env;
+
+      const formatted = Catch.formatExceptionForReport({ name: 'Error' });
+      if (formatted.url !== 'https://mail.google.com/mail/') {
+        throw new Error(`For path ${path}, expected URL to be 'https://mail.google.com/mail/' but got '${formatted.url}' (env: ${env})`);
+      }
+    }
+  } finally {
+    Catch.RUNTIME_ENVIRONMENT = originalEnv;
+  }
+  return 'pass';
+})();
\ No newline at end of file