Yes, it’s a buferring problem.
The video need time to buffer when seeking from the last frame to the first one when running “Auslage” timeline again.
You can extract the last frame image, show it over the video at the end of the video playback, then seek the video to its first frame after that. So the video is ready at its first frame when running the timeline again.
Please see your project fixed: van-trailer-fixed.saolapack (3.8 MB)
The video buffering time may vary depending on the connection speed, so the actual end time may differ from what was set in the editor.
I intentionally placed the image a little bit after the end of the video to ensure that it has ended.