A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Hi djowhite,
Thanks for using Microsoft products and posting in the community, I'm glad to offer help.
According to your description, I created a presentation with two portrait slides and opened it on iPhone, as you can see, the toolbar/notes will be hidden only in landscape mode. However, in portrait mode, even if I started the show, the toolbar/notes will always display on the screen, and there is no such an option could hide them.
Landscape mode:
We are sorry for the inconvenience to your work, in this case, I'd like to suggest you send feedback to Office to share your ideas, it would be helpful for Microsoft to improve the products, your understanding and contribution will be highly appreciated.
Reference: How do I give feedback on Microsoft Office?
Best Regards,
Arck