I have created a topic about small sweet spot and my observations with my own G2 where I believe there is either a calibration problem, or a hardware defect, otherwise the G2 optics could be designed in a certain way explaining why there are many reports of small sweet spots.
To get started you might want to read this short “to the point” illustration of the problem and the “workarounds” and post over there what do you see comparatively:
You might want to also read the OP in the aforementioned discussion for more details about what it is about.