Docker, host: network and Bluetooth

I’m having trouble with getting BlueTooth to work with my HAss container. I’ve had a search on the forums and found various people saying that I should use network: host so that the container can see the BlueTooth dongle. But if I remove the port mapping and add network: host, HAss never completes startup. This is the last thing in the log:

2018-04-16 20:23:10 INFO (MainThread) [homeassistant.components.sensor] Setting up sensor.ios

If I remove network: host and go back to ports: 8123:8123 it starts up fine but obviously can’t see the Bluetooth device.

This is my docker-compose entry

homeassistant:
container_name: home-assistant
restart: unless-stopped
image: homeassistant/home-assistant
#network_mode: host
depends_on:
- "postdb1"
- "mqtt"
volumes:
- /data/hass-config:/config
- /etc/localtime:/etc/localtime:ro
- /data/hass_media:/media
devices:
- /dev/ttyACM0:/dev/ttyACM0
- /dev/ttyACM1:/dev/ttyACM1
privileged: true
ports:
- 8123:8123

Does anyone have any insight on why this doesn’t work?

Thanks

Steve