BME280 No GND on QW/ST Cable?

I have a couple of BME280 PCBs, I am not measuring continuity between GND and the black V- wire on the QW/ST connector. All the other pinouts seem correct. Is there a known issue with this board? Is black not suppost to be connected to GND? Is it connected to anything else or am I able to just short them together on the board?

Is there a schematic for this PCB available anywhere?

EDIT:
Turns out the Adafruit library for the BME280 uses a 0x6* address, not 0x76. I made sure to pass the correct i2C address in the .begin statement and its now functioning. This issue was why I had started chasing grounds. Note to the manufacturer, a little LED on the board is a very useful diagnostic tool!

Hi Imogen

The schematic is linked on the shop page, here’s a direct link:

I think it’s the reverse polarity protection on the ground line that’s interfering with your continuity measuring.

I have a BME280 connected to my Galactic Unicorn via a QWICC cable. I haven’t measured the continuity but it is working fine. So is a RV3028 that is soldered to the BME280. They are both communicating via the QWICC cable / connectors.