Thanks again for the precise feedback! I made a note of the “Android app reverts meter settings after connection” issue. I left two meters logging all weekend, one at a 10 second interval and one at a 1 second interval. I think I saw the same thing happen when I reconnected to the 1-second interval meter.
Regarding the “chirp” of noise in buffer mode: I had not seen that issue. I just reproduced your setup and I can confirm that I see it now too. Every 6 or 7 screen refreshes there’s a chirp of noise. My suspicion is that this is on the app side, because the AC readings I took over the weekend look clean.
Thank you for finding this, I’ve made a note and will have a diagnosis soon!