Just a follow up. I contacted M5Stack tech support and they told me the old modules have pins that are 2.5mm and the new board has pins that are 3mm. So in theory I have the newer board but it separates from the Core2 fairly easily. Meaning the pins are probably making contact but not great. Will have to get longer screws and screw the module down to ensure good contact. For reference to separate from the Grey Core it is very tight and I usually use a screwdriver. I measured and the Grey Core lets the pins seat approximately 1mm more than the Core2. Here is a picture showing how to measure pin length. 0_1611190652059_Pins.jpg