I have a fairly unusual installation. I am running Firefox Quantum on Puppy Linux 6.0.5. I am booting an obsolete, underpowered (Intel Atom processor) netbook from a 4GB flash drive. This enables me to view videos (where they usually hang with a more conventional OS installation). However, I was not able to get audio working with the videos until I found the "Open in VLC" extension. It took me a while playing around with the extension before I got the hang of how to get it to work, but now I'm pretty happy with it. It works very well with You Tube videos. The setup is the only way I have been able to watch any videos streaming from the internet on this laptop.

If you are having problems with videos streaming from the net, you might want to give "Open in VLC" a try.