I captured video on this old Dell Inspiron PC aon VLC and it worked fine a week ago. Today I installed Linux Mint 19.3 Trica, and its recommended VLC version 3.0.8 Vetinari.
I open Browser Chomium Version 81.0.4044.138 (Official Build) Built on Ubuntu, running on LinuxMint 19.3 (64-bit), with DUckDuckGo. I open YouTube and start playing a video. I copy the URL and then open VLC and past the url into Media>Open Capture Device>Network Protcol and then past the URL. Hit Play.
The start of the video flashes on the screen for a fraction of a second then nothing.