Unable to use controller on linuxserver/steamos

[ct2057]

I recently set up linuxserver/steamos on my UGREEN NAS (DXP48000 Plus), turning it into somewhat of a clone of the recently announced Steam Machine - and something I've been wanting to do for some time. The image works flawlessly, and I can now stream games from my NAS to Steam Remote Play on my Apple TV, iPhone and iPad.

However, one issue I have found is that when I connect a controller (or indeed use touch controls on the iPhone or iPad), none - bar one that allows me to get to the Steam overlay - work in-game (any game). The controller is able to be used fine in menus however - so I don't think it's a controller issue.
I did think it could be something to do with Steam Input causing problems, and I did try disabling that before launching into a game, but Steam will not allow me to do that.

My Docker Compose file is below; has anyone else experienced this issue and/or resolved it?

Docker Compose:

version: "3.9"
services:
  steamos:
    image: lscr.io/linuxserver/steamos:latest
    container_name: steamos
    hostname: steamos
    cap_add:
      - NET_ADMIN
    security_opt:
      - seccomp:unconfined
      - apparmor:unconfined
    environment:
      - PUID=1000
      - PGID=100
      - TZ=Europe/London
      - DRINODE=/dev/dri/renderD128
      - STARTUP=BIGPICTURE
      - RESOLUTION=1920x1080
    volumes:
      - /volume1/docker/steamos/config:/config
      - /volume6/Steam:/steamlib
      - /dev/input:/dev/input
      - /run/udev/data:/run/udev/data
    ports:
      - 3000:3000
      - 3001:3001
      - 27031-27036:27031-27036/udp
      - 27031-27036:27031-27036
      - 47984-47990:47984-47990
      - 48010-48010:48010-48010
      - 47998-48000:47998-48000/udp
    devices:
      - /dev/dri:/dev/dri
    shm_size: "1gb"
    restart: unless-stopped

[j0nnymoe]

linuxserver/docker-steamos#27