Yes, I think that's a definite issue for the generation of Model 3 that I have. I had to disable sentry because it was taking a significant chunk too (and I didn't even bother putting a disk inside).
What I have seen is that the BMS may update its SoC estimate after driving, and I've seen it adjust the estimated SoC up or down by as much as 5% in some cases.
I get that from a planning perspective, it still stinks to have range than you thought you did an hour ago, but it's not all that different from the variation you might get with an analog dial on the gas tank, just that it's much easier to notice and track when it's digital and showed as a precise number.
https://imgdrop.io/image/IMG-2984.ADiI7
It's not the end of the world for driving around town with less than my whole family (which is 90% of my driving) but it's definitely annoying to come back to a car with 50% charge and see it with 43. I imagine it would be terrifying for a 20 -> 13, especially with the lack of supercharging infrastructure where I live (Calgary).
Does it only happen when you park in front of the garage at home, or does it also happen if you go out somewhere? For example, it might be struggling to connect to your WiFi at home (if you set it up with your home WiFi credentials) to download updates or upload telemetry, which would keep it awake longer than normal as it tries to make do with kilobits per second of usable bandwidth.
The issues do happen a lot in front of my house (which has very poor cell phone coverage). I've had lessor drops elsewhere.
I was wondering about the wifi myself too. I don't have wifi in front of the house and I didn't configure wifi either; I've actually installed wifi in my garage and left the car inside to see and I would get similar power losses.
I wonder if there is (a) a battery warming issue or (b) an issue because my phone w/ the Tesla app & bluetooth on is too close to the car, leading to it not going into standby mode? I don't think it is the former because it would be categorised differently (and it would not happen in summer). Turning off bluetooth on my phone everytime I come inside is honestly a bit insane and I would put that in the "It's a Tesla App problem"; but I don't hear about that issue from other drivers.
The real unfortunate part is that there is no way for me to get this diagnosed. It's been a problem since I bought the car, but it seems to be getting worse over time.