layers in layout don't apply to slides
I have a master slide that has a header (course title). The layout slide shows that header, as it should. I have created one layout for this master, and have added a text placeholder, and one layer (for navigation). The "navigation" layer contains one arrow and no triggers. The base layer of the layout contains a trigger to show the "navigation" layer at the start of the timeline. Very simple.
When I apply this layout to a slide, the course title and the text placeholder both show up, but the "navigation" layer (the arrow) does not. When I preview the slide, the "navigation" layer displays, as it should. Back in slide view, though, the "navigation" layer is not visible on the slide, and the layer is not present in the Slide Layers sidebar.
This seems like odd behavior, since I expected that any layer on a layout slide would transfer to a slide, just like any other object. How can I get this to work as expected?