My new g6 receiver keeps showing my BG around 40, One Touch has me over 100. I have calibrated a few times and also tried changing the sensor. Still show my lower than my actual BG. Any thoughts?
Is this the first day? Things can be off on the first day. Did you know that you may calibrate if you wish? I understand one calibration per day will increase the G6 accuracy. If you are concerned at all, I would call the helpline and report your experience to them. Is there any blood visible on the adhesive fabric? If the sensor is at fault, then they’ll send you a replacement. Good luck.
If by day 2 it’s still off, call Dexcom for a replacement. there are a lot of folks complaining about the G6, sadly. good luck!
I have that issue on the G5 on the first day. I don’t remember having it on the G4 really. It goes away on the second day usually. I have had quite a few frustrations with the G5, so I am hoping to hear more positives about the G6…
I had the exact same issue on the first night with my G5 (and sometimes with my G4 over the years).
My nighttimes always read much lower than reality (with any Dexcom), so I wasn’t surprised when it happened the first night with my G6. Interestingly, it was not the Low Alarm that ever went off, it was the “you’re going low and about to die soon!” Alarm 
As soon as I woke up (and it said it was low) I calibrated it and it’s been fine since.