HTML5 <video> not working in RU7100 (FW 1356) Tizen web app

My TV is a 65RU7100 - firmware 1356.

The HTML below works perfectly when running in the simulator. On TV, it successfully loads the video only occasionally (about 1 in 10 tries). I have tried loading and playing the video through javascript, but the issue persists.

I also have a program that uses AVPlay directly to play videos and I am getting the same problem. The videos almost never load. It looks like an underlying problem in AVPlay.

Simple HTML5 videos tested in the TV’s browser also do not work. Strangely, Youtube and Twitch works perfectly in the browser.

<!DOCTYPE html>
    <meta charset="utf-8" />
	<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
    <link rel="stylesheet" type="text/css" href="css/style.css"/>
    <script src="js/main.js"></script>
	<video id="video" width="400">
		<source src="" type="video/mp4">

Please, could someone from Samsung help me with this issue?

Can you tell me how u activated twitch tv? I have Samsung smart tv and I installed twitch tv there but I can’t do What should I do?

I didn’t activate twitch. I just use it through Samsung’s browser.

Hey Samsung, can’t you help me with my issue? Please someone from Samsung answer.