Navigation bar buttons disabled

Using Captivate 2019 v11.5.1.499.

I'm working on a project based on a template that I designed, and I'm running into a weird problem. When I test it, the bottom navigation bar only shows the mute, CC, and exit buttons. When I go into the Skin Editor to configure the playbar, the options to activate the play, rewind, forward, and back buttons are greyed out.

I tried different playbar themes but no luck. I created a new blank project, and also a new project based off the same template. On these two, all the buttons I want appear on the nav bar.

Is there a setting I'm missing?

Thanks,

Mike