Speaker view is flaky

[JaroCamphuijsen]

Sometimes the speaker view in presentations works, and sometimes it doesn't.

Expected behavior when pressing 's' on a presentation chapter:

When it doesn't work:

It is unpredictable, sometimes it works and sometimes it doesn't.

[JaroCamphuijsen]

Actually the speaker view is also not working properly when it does show up. The "current slide" window and "upcoming slide" window both show the whole NEBULA website, instead of just the reveal.js.