Libre Freestyle 2

Do people often get false readings compared to finger pricking?

They can differ quite a bit. I was surprised at my recent DAFNE Refresher day to be told that the Libre 2 is more accurate than finger pricking. There is a 5-10 minute lag between BGL readings and the readings from the interstitial fluid that the Libre 2 gets its readings from. It's not really an issue if your BGLs are flat, but if they are rising or dropping quickly, then you can expect a bit of a difference.

If you get false reading that cannot be explained its important to notify the manufacturer to allow them to look into it. If necessary they will tell you to change the sensor and send a free replacement. When using Freestyle Libre 2, Abbott often asked me to return the sensor to them for checking but Dexcom has never asked for a return.
When calling you will be asked for information about sensor, transmitter (if appropriate), activities around the times of errors, and the time of error and finger prick result. All manufacturers have a 'tolerance' level for errors and will advise if that applies.
Both Abbott and Dexcom have told me it is important for them to receive information about erroneous readings as it helps identify common issues or if there is a problem with a batch of sensors.
Making the phone calls are very beneficial for the user too. When I changed from Libre 2 to Dexcom G6 it was on the advice of Abbott because, they said, I might not be suited to Libre, and I am moving from Dexcom G6 to G7 following advice from Dexcom who identified the construction of the G7 might suit me better. Both manufacturers are more than happy to receive any calls regarding their products.