Changing a layout in Slide Master view does not finish the job for slides already built from it. If a revised placeholder arrangement appears on new slides but not on existing ones, check whether the updated layout has been reapplied.

This workflow uses desktop PowerPoint for Windows. Save a copy and identify a representative slide that should use the revised design. Note its current layout and any manual positioning that may need attention after the change.

Edit the layout that the slide actually uses

Open View, Slide Master. In the thumbnail list, the master is the top item and its associated layouts appear beneath it. Select the relevant layout, then make the intended placeholder changes. A descriptive layout name helps distinguish it from similar alternatives.

Close Master View. In Normal view, select an existing slide that needs the update, choose Home, Layout and select the revised layout. Microsoft explicitly requires this reapplication after layout changes such as adding a placeholder.

Test one slide before selecting a larger group. That makes it easier to see whether the chosen layout is appropriate and whether any slide-specific arrangement needs adjustment.

Verify content and future behaviour

Check that the title, body text and images remain complete and readable. Inspect manually added objects separately; do not assume every item on a slide is a layout placeholder.

Create a temporary new slide using the same layout and compare its structure with the updated existing slide. Remove the test slide afterwards. This checks both the revised design and the way it will support future additions.

Apply the layout to the remaining intended slides, then run through the presentation to find exceptions. Keep purposeful variations separate instead of forcing every slide into a structure that does not suit its content.

Save the accepted deck and explain which layout to use for new slides. A reusable layout is most useful when another editor can choose it confidently and obtain the intended structure without copying a finished slide’s accidental manual adjustments.

References: Microsoft: editing and reapplying slide layouts.