Abbott has issued a "device correction". Roughly 3 million devices provide inaccurate low readings due to a manufacturing problem. Inside that second link is a way for people to check the serial numbers and have them replaced by Abbott if it matches the one on your device.
https://www.fiercebiotech.com/medte...ms-after-incorrect-readings-and-death-reports
Home | FreeStyle - Abbott
https://www.fiercebiotech.com/medte...ms-after-incorrect-readings-and-death-reports
Home | FreeStyle - Abbott