I have 2 Pi Zero's, both with male hammer headers installed and an Envirophat with a female hammer header. When I connect the Envirophat to either pi and issue i2cdetect -y 1, i only see 3 of the 4 sensors.
If I run an example script or issue something like:
from envirophat import light
the leds on the Envirophat turn off and I get an error that seems to be looking for 0x58 in bmp280.py and throws an I/O error.
Running fully updated Raspbian.
My pin headers look flush and solid, and it doesn't seem to matter which pi i plug it in to.