Wish I could help you. Without being able to put my hands on the gun I'd just be guessing. Obviously something wrong with the GR Connector, as the gun works ok with the LW one. I've avoided the GR connectors because of the way they limit over travel. They may work fine when properly fitted, but seem a little Mickey Mouse to me. I use the LW connector and the LW "Ultimate Over travel stop" in my Glocks as part of my trigger work. Works great and easy to adjust over travel. I can only suggest you remove the slide, manually reset the trigger, and watch what happens with the trigger bar and connector. You may be able to see the problem and correct it. Good Luck.
Savage