@fraygon - I am sorry but now I am confused.
I am 100% sure I have use method with USB stick and I did not remove SD card from RPi.
This method is mentioned in few places (like this) but now on the official Home Assistant page is not described. 
With current description (adding data directly on SD card) there seem to be no need to add slash “/” in front of the “modules” folder.
What comes to my mind now is that if you trying to adjust folders using Windows computer - it might be a challenge as I do not think Windows file system can read Lynux one (used by RPi)…
Here is some info: I2c not working on the Pi4