add warning for iPhone QR-scanning behavior

front/src/components/QrReader/QrReaderContainer.tsx

@@ -22,6 +22,14 @@ const CAMERA_NOT_PERMITED_TEXT =
   "Camera access was denied. Please unblock camera access in the address bar and reload the page.";
 const CAMERA_NOT_PERMITED_TEXT_SAFARI_IOS =
   'Camera access was denied. Please allow camera access in the address bar by selecting AA > Website Settings > Camera > "Allow".';
+const IPHONE_WARNING_TEXT = (
+  <p>
+    <strong>Known Issue</strong>
+    <br />
+    We are experiencing problems with QR scanning on iPhone only. If you are also experiencing
+    issues, please contact us so we can add it to our investigation.
+  </p>
+);
 
 function QrReaderContainer({ onSuccess }: IQrReaderContainerProps) {
   const { baseId } = useBaseIdParam();
@@ -174,6 +182,12 @@ function QrReaderContainer({ onSuccess }: IQrReaderContainerProps) {
 
   return (
     <>
+      {isIOS && (
+        <>
+          <AlertWithoutAction type="warning" alertText={IPHONE_WARNING_TEXT} />
+          <br />
+        </>
+      )}
       {isCameraNotPermited && (
         <>
           <AlertWithoutAction