A subset of FreeStyle Libre 3 and Libre 3 Plus sensors can give falsely low glucose readings Only specific Libre 3 and Libre 3 Plus sensors are affected. Abbott, the manufacturer of FreeStyle Libre, has issued an urgent safety notice for some FreeStyle Libre 3 and FreeStyle Libre 3 Plus sensors ...
A bad sensor can give readings that are very far off the mark though it would be very unusual for several sensors to be that inaccurate. If the sensor is more than around 15 to 20% away from a finger-prick test, where the test is done around 10 minutes before comparing to the Libre and levels are flat and stable during time, and if three separate tests show that level of inaccuracy, then ...
Libre doesn't read blood glucose it uses relationship with the interstitial fluid and lags behind. You should carry finger pricker with you regardless if cgm or not. Instructions clearly state not to rely on it for medical decisions and should check via blood glucose highs and lows.
Libre 2 Plus - Worsening variation between sensor readings and glucose meter readings after around 8 days
Libre 2 Plus - Worsening variation between sensor readings ... - Diabetes
Libre 2 and Libre 2 Plus are exactly the same size. It is Libre 3 that's smaller and while I have seen it available via some online pharmacies, I can't afford it as it is more expensive. The fingerprick test and Libre CGM don't measure the same things, so I don't expect to have exactly the same reading.
if relying purely on cgm its advisable always to keep 1 spare. unfortuantly their customer service number: 08001701177 open at weekends and bankholidays 9am-5pm. weekdays is 8am-8pm. haven't ever seen install this app message. worth a try if its the official libre app. if that fails you can try the likes of xdrip or simular 3rd party software. have they got a flash glucose monitor, fingerprick ...