My question was about to be whether the meter was accurate. But if you have symptoms that confirm the meter - that is the answer IMHO.
Yeah - I would calibrate. That makes sense.
Obviously picking proper time for calibrate when you are straight and level on the cgm is critical.
If it was me, I would try:
Leave it in factory calibrate mode - no need for a restart.
Give it 4 calibrations and see if that pulls it into alignment with your meter and your symptoms. The BG number is not as relevant (assuming between 400 ~ 400 of course) as the cgm being straight and level.
Today, 2 calibrations approx 12 hours apart.
Tomorrow, 1 calibration
Next day, 1 calibration
One would hope that each calibration would pull it closer and after the 4th calibration, it would be looking good and no need for anything further.
Obviously (in case anybody else reading) this is VERY specific to a Dexcom G6 cgm system.