Example files not working in Firefox

[nmenu]

Some of the examples files are not working in Firefox (74.0.1 (64bits))

Here is one.

1. Load https://xeogl.org/examples/#objects_entities into Firefox
2. Click on "True" for ghosted for example, but any other will fail as well.

Results : You get a black screen as the call fails.

Doing the same in Google Chrome or Microsoft Edge works just fine.
Any idea why and how to workaround it ?
Thanks, Nico