I'm using PowerPoint in Office 365. I'm a long-time PowerPoint user and I'd like to think I'm pretty experienced with PP but I have found an issue I can't seem to find any kind of good solution for.

I have "Presentation #1" which was created initially in 2008 (in whatever version was current then). I've updated it a lot over the years: new slides, saving it, of course, in newer versions as I go along. It is saved as a ".PPTX"

I want to make a set of speaker notes (View->Notes Master) and set up the placeholders - headers, footers, etc - the way I want them but they don't "take" some of the slides. Only on newly created slides AND if I change anything trying to update the whole deck, the changes only "take" on slides created after the formatting changes I make.

So, I created new "Presentation #2", in PP 365, set up my Notes Master the way I want it then copied and pasted the slides from "#1" into "#2" using Destination Theme AND tried using Source Formatting and, in both cases, when I print (PDF, printer, makes no difference) some slides have the old Notes Pages format, others (more recently created) have the new format.

I can recreate a new slide in "#2" and it adopts the current Notes page formatting. Anything from the original set OR if I copy and paste from "#2" back into "1" some slides retain one Notes formatting, others take on the other.

It would seem that old slides want to retain the old format and are "reluctant" to adopt a new format - "old slides, new trick..."

Bottom line: I want all my Notes pages formatted the same way and I can't find a way - in Office, PowerPoint 365 - to apply the Notes Master formatting to all the slides. Going back through and generating new slides and then copying old content into the new slide is far too time-consuming (there are a LOT of slides here, this is a whole class).

Is there something like using the Format Painter on text or changing Slide Master settings, is there a way to get these all to adopt the same Notes format that I've missed?!?