Hello Gunther,  I have had a lot of sequences that seem to come out smeared or fail to render all the way.  I would like to select 4k but my computer, Dell PC laptop is unable to play the 4k mp4 file so I have to render it to a 1080p in Premiere Elements in order to view the file at all and PE often has trouble with the 4k files.  I have found 3k HQ without the motion blur seems to work best.  Please let me know if you have any suggestions, I like to Lrtimelapse render at original resolution, so I can pan & zoom a little in final render in Premiere Elements.  When selecting original resolution for rendering, are we supposed to not select anything like 3k or 4k at same time?

Here's a screenshot (attached) of my latest example which shows this smearing effect, produced with Ver 4.5, this was produced with the 3k HQ plus the motion blur and also selected original resolution, and cropped & rendered with Premier Elements at 1080 so I can watch it.
 
Here's a screenshot (attached) of the sequence preview and table.

Which player is that? I assume the player is the problem.
Try the MPC player on windows, it will play the higher resolutions, the windows players won't.
https://mpc-hc.org/

I see no difference with the MPC player as far as the bleeding and banding, here's another screenshot from MPC, attached, this one was rendered at 4k HQ without the motion blur selected, done with earlier ver 4.  This is straight out of Lrtimelapse rendering.

Never saw an effect like that. Can you upload a MP4 file somewhere?