Return code: 127 running Mosquitto command

Installation Home Assistant OS
1

Just moved over from Hassbian to Hassio and everything is working great apart from a shell command that I use for changing channels via IR to my satellite box - the code works ok on Hassbian. Just wondered where it is failing.

Here is the error

Error running command: mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 -m “573503” && mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 -m “536783” && mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 -m “573503”`, return code: 127

/usr/lib/python3.6/site-packages/homeassistant/components/shell_command.py (ERROR)`

And here is my Mosquitto add on settings

{
  "plain": true,
  "ssl": false,
  "anonymous": false,
  "logins": [
    {
      "username": "myusername",
      "password": "mypw"
    }
  ],
  "customize": {
    "active": false,
    "folder": "mosquitto"
  },
  "certfile": "fullchain.pem",
  "keyfile": "privkey.pem"
}

here is an extract from the shell.yaml

  ###############
  ##### Humax #####
  ###############
  wemos_bbc1 : !secret bbc1
  wemos_bbc2 : !secret bbc2
  wemos_itv : !secret itv

and finally the command from the secrets folder

bbc1: mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 -m "573503" && mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 -m "536783" && mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 -m "573503"

If I run mosquitto_pub -u myusername -P mypw -t home/commands/IR_NEC/IRBITS_32/RPT_4 with a payload of 573503 from within HA Dev MQTT ir runs the command fine.

Any ideas how I can get this command to run ? Thanks