@madusmacus
I have exactly the same, that when I stand up from lying, the Libre indicates my bg is rising fast.
I think it could actually be true, that your bg rises when you stand up, since your body switches from 'rest-modus' to 'active modus'. However the Libre seems to slightly exaggerate the rising blood levels while standing up.
However I found out, thanks to the Libre, that my blood sugar rises when I stand up in the morning, and that I have to take pretty huge amounts of insulin even without having breakfast. It's the same if I go from sitting or normal activity to the gym.
So conclusion, it's in my case no nonsense that the Libre indicates higher values when I stand up. But I'm curious, if you just stand up shortly to go to the bathroom and than go back to bed, if your bg actually rises or if it's a Libre glitch. Didn't bother to check that yet with normal BG meter.
Anyway, glad to hear it's not just me.
About an alternative spot: I have used the Libre on my upper lesg successfully for quite some time, but lately it was giving some trouble. Note that Abbot does not replaxce faulty sensor that have been placed on your leg.