The media server or MCU adds padding around the presentation content to maintain aspect ratio.
Now if the presentation source has black borders on its edges, then the media server could misinterpret this and it could result in the inadvertent cropping of the presentation.
Issue is only seen on recording when soft clients present. Same issue is not seen if an XT endpoint was connected in H.323 mode and presenting.
As you can see from below example, the upper pictures are the original PPT source while the lower ones are the screen captures from the recording.
The PowerPoint (PPT) on the right side will show as cropped on the recording as the source PPT as black bars on the sides (left and right).