diff and comm are not finding difference between two env files

I have this env file

• 1.env contents:

  BARF_BAG=1

then another env file:

• 2.env contents:

  BARF_BAG=2

I run comm and diff on the files to see the difference:

#!/usr/bin/env bash

(
  set -e;

  first_env_file="$1"
  second_env_file="$2"

  if ! test -f "$first_env_file"; then
     echo 'first arg must be an env file';
     exit 1;
  fi

  if ! test -f "$second_env_file"; then
     echo 'second arg must be an env file';
     exit 1;
  fi

  echo -e '\n'
  echo -e 'displaying results from diff tool:'
  diff <(. "$first_env_file"; env | sort) <(. "$second_env_file"; env | sort) || true
  echo -e '\n'
  echo 'displaying results from comm tool:'
  comm -3 <(. "$first_env_file"; env | sort ) <(. "$second_env_file"; env | sort) || true
  echo 'finished diffing env files.'
)

and I get nothing, just:

displaying results from diff tool:


displaying results from comm tool:
finished diffing env files.

what gives?