So it is not a BI problem if it is the same with VLC.
Looks like a low frame rate on the cams. You could use the BI Status window to see what the FPS reported is.
The Cams are set to 20FPS internally and BI says 20.10FPS Bit Rate 613.55kb/s
I have noticed that if I raise the cams up to 25(max FPS) intenally and then adjust Blue iris it gets better, but the glitch is still there slightly.