Multiple pages / layouts in one Impress template

I am trying to create a custom template that defines multiple slide types (I think Libreoffice calls these “layouts”). For example, I would like my template to include a title slide (with banner image) and a regular content slide (with no banner image). I want to be able to start a presentation with that template then apply layouts to different slides, causing it to import my custom settings.

I’ve tried doing this by

  1. defining my slides as I want them, ensuring they have the relevant “layout”.
  2. File > Templates > Save as template.

When I create a new presentation with this template, my title slide and banner images import correctly, but then if I try to add new slides (e.g. a “Title and Content” slide) they appear as the default Libreoffice theme rather than my custom slides. Why are my other custom slides not being applied?