I can't answer your question but: you might like to consider semi stripping the rifle to remove the trigger unit. then remove the plate from the trigger to expose the workings. This will let you adjust the adjusters to set the trigger how you want it.
I had the same issue with an LGU I bought s/h ... I just could not get the trigger set correctly, but with the cover off I could see what was happening as I turned the adjusters ... my trigger was way out.
There are several guides on the net on how to do the above.
Cheers, Phil