When you viewed olebisk_'s YouTube video, did you view it as YouTube Full Screen?
I viewed this video as non Full Screen and Full Screen YouTube video with my 19 inch Widescreen computer monitor set at its native resolution of 1440 x 900.
The playback of the non Full Screen YouTube video does not present to me with any problems of note.
However playback of the Full Screen YouTube video does present with flickering (for want of a better word) around text at the end. The overall Full Screen YouTube video quality should also be looked at in this regard.
But I would not attempt any suggestions until I had a lot more details of the project, such as,
Version of Premiere Elements and computer operating system
Properties of source media
Export Settings (and from within Premiere Elements versus Timeline exported to file and then that file uploaded to YouTube at the YouTube web site).
Right now based on what I saw in my computer environment, my only suggestion for this specific video would be to avoid Full Screen YouTube video.