Hello Mianakif,
Let's use the steps below to see if you are able to mirror your iPhone screen to your TV:
1. Connect your iPhone or iPad to the same Wi-Fi network as your Apple TV, AirPlay-compatible smart TV, or Mac.2
2. Open Control Center:
• On iPhone X or later or iPad with iPadOS 13 or later: Swipe down from the upper-right corner of the screen.
• On iPhone 8 or earlier or iOS 11 or earlier: Swipe up from the bottom edge of the screen.
3. Tap Screen Mirroring
.
4. Select your TV or Mac from the list.
5. If an AirPlay passcode appears on your TV screen or Mac, enter the passcode on your iPhone or iPad.
To stop mirroring your iPhone or iPad, open Control Center, tap Screen Mirroring, then tap Stop Mirroring. Or press the Menu button on your Apple TV Remote.
You can also find those steps in this resource: Use AirPlay to stream video or mirror the screen of your iPhone or iPad - Apple Support That should help to isolate this behavior further.
Additionally, does this occur with multiple websites with video content?
Let us know, and we'll keep moving forward from there.