Hi Steven,
Hmm, what is the max resolution of your third monitor that you are trying to achieve?
We specify in various areas of the product page that the maximum supported resolution of the UGA-3000 adapter is 2048x1152 (1920x1080 with Analog VGA). If you’re trying to drive a 1440p monitor or higher, then the UGA-3000 adapter is not a compatible fit.
EDIT: You had mentioned one of your displays is a HP 27n G2 display, which I see is a 2560x1440 monitor. However, I’m not sure the resolution of the other two displays you are using.
Thanks!
Mitchell