Firefox - Media Browser - not playing movies

I’m testing the Media Browser in several browsers. I have some movies (mov, mp4, m4v) in my Local Media.

Replay in iOS app, Safari, Chrome (on macOS) works fine

In Firefox (my favorite browser) the movie does not start (spinning wheel), but I see a lot of network traffic after opening the movie.

In the console I see the following error:

Failed to load ‘https://[home-assistant]/media/local/tenerife.m4v?authSig=eyJ0eXAiOiJKV1....’. A ServiceWorker intercepted the request and encountered an unexpected error. service_worker.js:1:11014

Any suggestion to troubleshoot?

Actually I solved it myself. Firefox requires the “Optimize for network use” option. This option is available when compressing the movie.
When selected, the movie shows in Firefox.