the video is running smoothly without buffering for both sources.
but the video buffering is not the problem and even if the video shakes it is not the main concern of this issue.
the main problem is that the slides are not shown properly, some are skipped in the littel previews below and the main slide is skipping or showing the next slide for 1/2 second and then a still image of the video, etc. but for this i have you already provided a screenvideo?!
i don't hope the 11 answers before have not been for nothing?
to avoid wasting any more unnecessary time i have created the screen video again, see attached.
the problem don't happen if the video is not on the first slide but the customer want's it on first slide.