My board works fine with one exception, the reset button doesn’t work. When I ohm it out I found it is connected to pin 16 of the IC, not pin 1. I have two of these backpacks, one still unassembled, and both show the reset connected to pin 16.
The explanation is simple. It is not a reset button. It is a button that you can use for input, as documented on the product page: https://nootropicdesign.com/matrixbackpack/