Sorry, no answer, but I am having a similar problem. I am trying to use adafruit-blinka on a Pi Zero W. Starting from a clean SD card I have installed the Rpi OS and I have done a manual blinky install as documented by Adafruit.

I am using a virtual environment. If I run a python3 "shell" then import board and dir(board) seem to work just fine.

If I create a python script containing "import board" it fails reporting "module board not found".

Any Clues, Cheers