converters = BAD!
Your monitors only have vga inputs? UG!
What resolutions and refresh rate have your monitors?
Try to use only one HDMI to VGA connection(unplug another monitor)
But it looks like your HDMI-VGA converter is faulty.You may try another HQ HDMI to VGA converter or DP to VGA adapter.
Also check or change your VGA-VGA cables.