To record Netflix using OBS, you must make some changes in Chrome to avoid Netflix's DRM protection and, thereby, the black screen that usually appears.
I used OBS with the default settings to record a DRM-protected streamed video. For some reason, it recorded audio, but the video within the web page in Chrome ...
If content is DRM-protected, it's always black. There is no possible technical workaround. It will stay black even if you buy a hdmi capture card and record ...