Thanks for the response. I replaced the grove cable with another grove cable and made sure it was fully seated and still got an error.

>>> import units
>>> a = units.E
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'E'

>>> a = units.ENV(units.P)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'P'

>>> a = units.ENV(units.PORTA)
>>>

Tried this as well:
>>> from machine import I2C
>>> i2c = I2C(freq=400000, sda=21, scl=22)
>>> Traceback (most recent call last):
File "boot.py", line 29, in reboot
File "m5flow/hardware/axp192.py", line 96, in btnState
File "m5flow/hardware/axp192.py", line 103, in _regChar
OSError: I2C bus error (6)

>>> i2c.scan()
[52, 81, 108]
>>> Traceback (most recent call last):
File "boot.py", line 29, in reboot
File "m5flow/hardware/axp192.py", line 96, in btnState
File "m5flow/hardware/axp192.py", line 103, in _regChar
OSError: I2C bus error (6)

While using the M5StickC with the ENV "environment sensor" connected I receive the following error when running the ENV sample UICode program (https://github.com/m5stack/M5-ProductExampleCodes/tree/master/Unit/ENV/UIFlo):

>>> env0 = units.ENV(units.PORTA)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "m5flow/units.py", line 83, in init
File "lib/bmp280.py", line 147, in init
OSError: I2C bus error (6)

I tried a second ENV sensor and received the same error. Any suggestions would be appreciated.