[Python] Video/media resource blocked by OpaqueResponseBlocking when loading via API in Python...

I'm building a learning platform where my Python backend fetches media URLs (like video/audio) from APIs (e.g., Unsplash, YouTube, or custom content servers) and sends them to the frontend. When the frontend (browser) tries to play or embed the media, I get the following error in the browser console: “A resource is blocked by OpaqueResponseBlocking, please check browser console for details. All candidate resources failed to load. Media load paused.”

// LessonPage.js
import React from "react";
import { useLocation, useNavigate } from "react-router-dom";

function LessonPage() {
const location = useLocation();
const navigate = useNavigate();
const { lesson } = location.state || {};

if (!lesson) return <p>No lesson data available</p>;

const imageUrls = lesson.image_urls || [];
const videoUrls = lesson.video_urls || [];

return (
<div>
<h2>{lesson.topic}</h2>

<h3>Images</h3>
{imageUrls.map((url, i) => (
<img key={i} src={url} alt="lesson" />
))}

<h3>Videos</h3>
{videoUrls.map((url, i) => (
<video key={i} controls>
<source src={url} type="video/mp4" />
</video>
))}
</div>
);
}

export default LessonPage;


What I've Tried:

• Fetching media URLs directly from the API (server-to-server in Python).
• Passing those URLs to the client for video/audio playback using <video> or <audio> tags.

1. What causes the OpaqueResponseBlocking error in this case?
2. How can I safely proxy or load such media through my Python backend to avoid this issue?

I'm using Flask (or Django) on the backend and vanilla JS/React on the frontend.

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