grains not syncing

# grains in /etc/salt/minion
grains:
  roles:
    - log-forwarder

# salt state to set additional grains
testing additional grains:
  grains.list_present:
    - name: roles
    - value:
      - nginx

# Salt grains state run
salt log_forwarder state.apply nginx
log_forwarder:
----------
          ID: nginx
    Function: pkg.latest
      Result: True
     Comment: Package nginx is already up-to-date
     Started: 13:34:40.226560
    Duration: 11133.219 ms
     Changes:
----------
          ID: roles
    Function: grains.list_present
      Result: True
     Comment: Append value nginx to grain roles
     Started: 13:34:51.360453
    Duration: 10.621 ms
     Changes:
              ----------
              new:
                  ----------
                  roles:
                      - log-forwarder
                      - nginx

Summary for log_forwarder
------------
Succeeded: 2 (changed=1)
Failed:    0
------------
Total states run:     2
Total run time:  11.144 s

# confirm grains
salt log_forwarder grains.item roles
log_forwarder:
    ----------
    roles:
        - log-forwarder
        
# /etc/salt/grains
salt log_forwarder cp.get_file_str file:///etc/salt/grains
log_forwarder:
    roles:
    - log-forwarder
    - nginx