Data recording position moves "unintentional"

firstly, sorry for my poor english.

My DSO203 has a strange behavior when operating without trigger at slow recording speed. The measurement position moves unpredictable every few seconds, as I show in first 20 seconds of (unfortunately, forum’s spam filter does not let me mark this as URL).

Because it seems that no one has ever reported this as a software bug, I thought that this is a hardware problem and, therefore, I returned the DSO shown in the video. But now I received a second DSO from another dealer which has exactly the same behavior.

Does anyone have the same problem with his DSO203? Is there a solution? My Hardware Version is V2.72, Software SYS 1.60, FPGA 2.61, APP 1.12. Upgrading firmware to SYS 1.62 and App 1.13 from Seeedstudio Wiki has improved nothing.

Greetings from Germany