Can confirm that Firefox works. Wasn't working with Chrome and it stopped recently (April 2022).

Temporary solution for Chrome
 

Found a way to fix it temporarily for Chrome. In settings go to: Use hardware acceleration when available, turn it off, relaunch and the issue will be fixed. Still not ideal as it brings other issues such as camera does not work properly for Google Meet sometimes but it fixes video streaming issue.

This works for me. Thanks.

Worked for me as well! thank you!

Finally a solution
 

I had the same problem and found out if you use the Firefox web browser it works.

Enjoy life with streaming and display extension.

Same solution for Brave
 

I think this solution applies to all Chromium base browsers.
I'm using Brave and everything was working fine until yesterday that I received a new brave update.
You need to open the setting and find: Use hardware acceleration when available, turn it off

TV app not working
 

Hello, I have used the fix in Chrome browser mentioned in this thread and it worked, but when trying to watch purchased content on apple's TV app, i have the same issue experienced with Netflix etc. (sound, no video).

Anyone find a solution for this?

Same issue...
 

I'm a little stressed... I just spent two days trying to troubleshoot Netflix, HBO, Amazon Prime and such streaming services... at first I was getting a constant black screen and couldn't determine cause.

If. I remove my D6000s device and turn off DisplayLink application for Mac, I can run the above streaming services without a single problem. However as soon as dock is added with my 2x 2k (2560x1440) all 3 displays including the Mac inherent display stops streaming services immediately with just black screens. I quite furious right now. The issue seems to be related to something with HDCP digital copy protection in affect when it should not be failing here. This doesn't exist for Windows laptop and identical hardware.

Has DisplayLink replied to anyone within this support thread?

I tried the above with Chrome, Safari, Firefox and Vivaldi and all black screens. If I disable hardware acceleration I can get playback on Prime Video however the quality is unacceptable for any device standard for play back.

Fix (kind of)
 

I downloaded Firefox and Opera and it works just fine, it appears to be that chrome and safari are the issues.

I really hope that they fix this quickly tho...