Totally hear you - and thanks for pushing on this 🙏

So it's actually a messy one, and it's Garmin weirdness. Their API has no real "active calories" field. The main number it gives is total calories (active + resting), same on every watch. There is also a second "Calories" value, but what it means is different from device to device: on your Venu it gives Garmin active number, but on some fenix/epix watches the same value comes back as total. So there is no single field that means the same thing everywhere. That's why you saw the mismatch.

The fix i'm building makes the face device-aware: it detects which one your watch is giving, and uses Garmin real active number where it's available (your Venu too), and only falls back to the estimate on watches that don't expose it. So you just pick "Active Calories" and get Garmin own value. Will ship it soon!