NAV doesn’t automatically take you to the magenta line anymore - that was an erroneous behavior that could not be fixed until Working Title rebuilt the G3000 starting in AAU1.
NAV or GPS will “arm” showing in white on the Annunciator Scoreboard. You must manually fly or use a mode like HDG to intercept the magenta line at a 30 degree angle. When the aircraft is within 2 dots of the desired track, HDG will extinguish and NAV/GPS will start blinking, eventually turning solid Green. By then the plane will have banked to align with the flight path and start tracking true.
This is real-world Garmin FMS behavior.