Maybe you are not logged into YT in StreamFab? (could explain the cookie issue)
I thought I would try, but with the best I can make out of the link from the screenshot, when I try, YT claims Video unavailable.
Maybe instead of pasting the link via Paste URL, paste it into the StreamFab address bar.
xx-Paste URL option:
Pastes into the SF address bar:
I also have this setting off, as it caused issues for me. Monitor clipboard ;/
