When I send my camera triggers in batches of 12 at a time, sometimes an extra image or two are returned.
I tried the example VI attached to the following discussion
https://forums.ni.com/t5/Machine-Vision/ACE-GigE-external-trigger-example-needed/m-p/2887420
Also tried the example that ships with LabVIEW
\examples\Vision Acquisition\NI-IMAQdx\Basic Acquisition\Acquire Triggered Images.vi
Camera Model: Basler acA2000-50gm