streaming service videos not playing when connected to external monitor.

Thanks for the reply, Iamrohan77.

To confirm, have you had a chance to test if this continues when using different cable? A non-HDCP compliant cable might be causing this issue. (note from the article below, Netflix requires HDCP 2.2 rated cable for UHD videos or If using a cable or adapter, it must support HDR).

If the cable isn't the issue and this seems to be only with streaming content from providers, what settings are you using for the video quality? HDR? As an example, this is from Netflix showing their requirements:

How to use Netflix on your Mac computer

https://help.netflix.com/en/node/55764

"Netflix in Ultra HD

To stream in Ultra HD (UHD), you need:

• A Mac computer with an Apple processor or Apple T2 Security chip, and built-in UHD-capable display.
• macOS Big Sur 11.0 or later installed.
• The latest version of Safari browser.
• If connecting to one or more external displays, each connected display must have a minimum 60Hz refresh rate and UHD/4K resolution, and be connected using a HDCP 2.2 rated video cable.
• A Netflix plan that supports streaming in UHD.
• A steady internet connection speed of 15 megabits per second or higher.
• Streaming quality set to Auto or High.

Netflix in HDR

Netflix supports two High Dynamic Range (HDR) video formats, Dolby Vision and HDR10. If your Mac meets the requirements below, TV shows and movies available in HDR will display the HDR or DV icon next to their description.

To play HDR content on your Mac computer, you need:

• The latest version of the Safari browser
• A compatible Mac model with an HDR-capable display
• macOS Catalina 10.15.4 or later
• If using a cable or adapter, it must support HDR
• The Apple XDR Display preset or High Dynamic Range checkbox turned on in System Preferences > Display
• The Optimize video streaming while on battery option turned off in System Preferences > Battery"

You may need to contact the other providers for their requirements.

Review this article for any HDR settings needed on your MacBook: Play HDR video on Mac - Apple Support

All the best.

Iamrohan77,

Thank you for keeping us posted.

We recommend that you check if the issue persists when signed in on a different user account. 

The article below can help if you do not have any other user account to test with.

Set up users, guests, and groups on Mac

If you are not experiencing the issue on a different user account, we recommend that you reach out to us here so we can take a closer look into the issue: Get Support

Otherwise, keep us posted here. Let us know if there are any features or apps running in the background.

Take care!

Hello Iamrohan77,

To help us get a better understanding of the issue, we’d like to ask a few questions.

1. Does the external monitor function as expected when not playing a video?
2. When this issue happens, do any errors appear? If so, what does the error say?
3. When the issue happens, does the video stop playing only, or does the external display appear to not be detected, or look blurry?

The above information will help us determine how to proceed.

In the meantime, please check out this link which has information on external display issues, and may help: If your external display isn't detected or appears blurry when connected to your Mac

If your display is blank or not detected

Try these steps if you don't see an image on your display.

Check your cable or adapter

Disconnect the cable from your external display from your Mac, then reconnect it. If the cable from your external display doesn't connect to the ports on your Mac, you can use a USB-C or Thunderbolt adapter. If you're using a USB-C or Thunderbolt adapter to connect a display, the adapter must be compliant with DisplayPort Alt Mode or Thunderbolt / USB 4.

Check how many displays you can connect

If you're connecting multiple displays to your Mac, use the Tech Specs page to find out how many external displays your Mac supports.

1. Choose Apple menu  > About This Mac, double-click your serial number, then press Command-C to copy it.

2. Go to the Tech Specs page, click the Search Tech Specs bar, press Command-V to enter your computer's serial number, then click Search.

3. Click the specs page for your Mac. The number of displays your Mac supports appears under Video Support or Graphics.

Thanks!

Iamrohan77,

Based on the troubleshooting that has been completed, and you've confirmed the external display is working fine, use Apple Support to connect with AppleCare support to investigate further.

Have a great day.