New Template settings don't stick

Windows 8.1 Pro, LO 7.4.6.2, File format .otp and .pptx
I followed the directions in the 7.4 Impress Guide, way down in the Creating Templates section, but the new template doesn’t “stick.” Here’s what I mean: I created a new presentation with the new template. New Slide has the proper fonts, etc. I save the new presentation for later and exit. Later I open the new presentation, choose New Slide, and it has all the old settings from before set the values in the new template. What gives?

This? Does it also fail if you use ODP?

Note that to test, you need to create a new document from the template, not to save your PPTX as ODP.

Thank you, @mikekaganski, I delayed responding to test this quite a bit. Using odp from scratch produces different results. After carefully following the instructions in the Impress Guide to create new template, both from existing template and from a small odp presentation, and carefully setting up the fonts, etc. New Slide in a new presentation with the template always gives me a blank slide instead of what I designed.

Then you probably have only one slide saved as a document template and not a modified master slide.
See:

My Master Slide in Impress


English documentation