Hi,

When I drag & drop slides from one presentation to another, PowerPoint adds the slides' source layouts to my destination template instead of using the existing destination layouts (which have the same amount of placeholders, and even the same layout names).
Why is that??

To elaborate:
I really mean "Layouts" (smaller thumbnails / no number in front of them) not "Slide Masters", and I understand the difference between "Keep Source Formatting" and "Use Destination Theme". That's not the issue. (Of course I use "Keep Source Formatting in this case).

If I use two of the built-in PowerPoint themes and drag & drop slides between them, PowerPoint recognises the destination layouts, and the total number of layouts stay the same.

However, if I use two bespoke templates: PowerPoint adds new layouts, all underneath the main Master.
Even with the most basic of slides:

• I have a source slide with Title Placeholder + Subtitle Placeholder + one content placeholder, all filled with content. Layout Name "Basic Content slide".
• The destination file (different theme/colors/fonts) has an existing layout with the exact same placeholders, and the layout is also called "Basic Content slide".
• Drag and drop the slide
• Colors, fonts etc all change, so that's great... but:
  Suddenly, at the bottom of my destination file's layouts list, there's a new layout called "1_Basic Content slide"

How can I get PowerPoint to use the destination file's existing slide layout?
Like I said – it works with MS built-in templates, so it must be possible.

Many thanks for your help!!!