Firefox Video Playback issue in VMWare Ubuntu virtual machine.

I installed Ubuntu v19.10 in a VMWare virtual machine (running Workstation 15.5), and discovered an issue with Firefox in this environment.

If you go to www.cnn.com, and then attempt to play any of their videos, you get a "forever spinning circle" and a message at the upper left part of the video that says "Something went wrong during native playback."   This happens no matter which video I select.

I went to www.yahoo.com to see if their videos would play, and in that case I get a "Video Not Available" message, with a subtext that says "Unfortunately, this video is missing or damaged and cannot be played" -- but in this case there's no "forever spinning circle".

If I go to www.youtube.com and play one of their videos, everything works fine.

Just for grins, I installed Chromium, and all of the videos play perfectly in this browser.

Interestingly, Firefox works fine for all of these in virtual machines I set up for a couple other Linux distros -- Elementary v5.0 and Linux Mint v19.2.

Just for grins, I also installed the latest LTS version of Ubuntu (v18.04.3) … and it has the exact same issue with Firefox.

Any ideas ??