Does the BME680 breakout have pullups on the I2C lines? I’ve looked round and can’t find (or have overlooked) any circuit diagram.
Looking at the photos, it looks like it might have a FET-based logic level shifter on board, and there’s a sprinkling of SMD labelled 472, which I might think are 4k7 pull-up resistors, except I can’t quite see the traces well enough to be sure. (Though noting that the device works at 1.2-3.6V I observe it wouldn’t need shifting on a pi).
I’m nervous because I would want to put it on a bus that already has a few devices on it. Those devices are on Adafruit breakout boards, and they customarily put 10k pullups on board. The I2C specs say pullups should not be less than 1k0 for a bus at 3.3V, and if it is 4k7 pullups, I’m going to exceed that limit if this goes on the bus with the other devices already there. In that case, with the 1k8 on-board on the pi, this on its own gives a total 1k3. I can just squeeeze two more 10k on (total effect than 1k03) before going below the allowed minimum.
Of course, I could then do some desoldering, but I’d want to know which to desolder, so a circuit diagram would be nice…