Hello,
Unfortunately devices with DisplayLink technology do not support HDCP in macOS environment.
Streaming services like iTunes, HBO, Amazon Prime, Netflix or Disney+, YouTube TV etc. are using HDCP protected content. This is currently one of the DisplayLink limitations.
In those cases the video would remain black while audio is still playing. Please take a look at this article:
Content protected video does not play on Mac while DisplayLink screens are connected.
Due to limitation on our end it is expected that this feature does not work. I get a feedback from many users that it is worth checking other browsers, any that were using Chrome have success with Firefox now. I hear that also changing the hardware acceleration settings in the browser helps.
Best regards,
Daniel