I've just had my first potentially-serious issue with the Libre. I was feeling pretty ropey and thinking I'm heading rapidly into a hypo. I was nowhere near my BG testing kit - I know, I know LOL. Anyway, I hurried back to where it was and was feeling like things were getting bad - it was about 5 minutes away (and I know you're all going to quite rightly say I should have corrected and worried about testing later, but I wanted to see what each device would register). Sure enough, Mobile registered at 2.9, Libre scan was registering 4.2 and horizontal arrow. I corrected straightaway, so I can't tell you if the Libre would have caught up 10 minutes later, but I guess I would have expected to see a 'rapid-drop' arrow if that was going to be the case. No indication of anything wrong. On this occasion, I'd say the way I was feeling would point at the Mobile being more accurate. Anyway, I'll download the data from Libre later and check what it really thought was going on at that time.
I'm fine BTW - no harm done - and the little Mars Celebration was the perfect hypo treat(ment)!
Smidge