Hi @petar82 and welcome to our forum,
Despite the fact that this is more of a support request not related to CVB, it is a something a lot of people run into using GEV Cameras and what we also addressed before in this forum our in our documentation.
Packet loss and how this is visible
You are seeing packet loss while transferring the data. By default, in CVB, we use packet resend. If some packets are lost, they are resend and we receive a complete image. If we are loosing too many packets, the packet resend mechanism makes this worse as it uses more network bandwidth resulting in even more packet resends.
The fact that you see that only while moving something in the image is related to the acquisition buffers, which are used and not reset for every image. This means if you lose packets, a part of the image is not updated. If nothing is moving, the image data is nearly the same, and you do not see that in the image. If you have movement, you see old data in the area of the image which is not updated. Mostly visible as lines in the image like your screenshot in your post.
Configure stable GigE Vision network connection:
This section in our CVB Online Help describes the steps to optimize the network settings to prevent lost packets.
Multicamera setups
Even with an optimized network setup, you will face packet loss issues while using a multi camera setup and not further optimize your camera setup.
The Following Post describes what to do in this situation:
Pixels of previous image visible in current image - General Questions - Common Vision Blox User Forum