Hantek 4032L double-edges problem

KDE

Hi!

I've just purchased Hantek 4032L logic analyzer and have encountered the following problem: I connect a pure square wave 1 MHz generator to its inputs (to four of them for sure - A0, A1, A2 and B2) and instead of clean square wave I sometimes see double-edged waves:



So I've tried lowering the input square wave frequency to 1 KHz and sample rate down to 10 KS/s and stll sometimes see these "double edges", so it is definitely not a signal transition issue. I've tried connecting LA to another PCs using another USB cables - there is completely no difference, I always see these "double edges". I also have checked the input signal with oscilloscope in both cases (1 MHz and 1 KHz) and it is perfect - there are no any "double edges" or even transition spikes at all. So it is an LA issue.

What is this and how do I get rid of it?

Thank you.

KDE

The input signal has the standard CMOS levels - from 0 to 5 V. I've tried different LA's threshold settings with exactly the same result.