That’s not shocking at all. My Dex is always wrong like that. I will have corrected and be on my way back up and the Dex will be showing me in the 40’s. I am glad other people are noticing this sort of stuff.
While you were gone, a bit of a debate between the value of CGM vs BG:
https://forum.fudiabetes.org/t/what-my-dexcom-often-looks-like-when-running