Unable to access devices in rootless container

[twinoijsdrfg]

I have set permissions on my devices to allow read access to anyone, I'm passing them correctly and I can see them, but I can't use them. I haven't been able to find any kind of best practice guide for this so I don't know if I've done everything I need to do.

I'm running Frigate and when I start it it doesn't recognise either my GPU or my TPU. Here's my compose file:

services:
frigate:
container_name: frigate
restart: "no"
image: ghcr.io/blakeblackshear/frigate:stable
shm_size: "256m" # Set shared memory size
volumes:
- ./config:/config
- ./storage:/mnt/CCTV/storage
- type: tmpfs # Optional: 1GB of memory, reduces SSD/SD Card wear
target: /tmp/cache
tmpfs:
size: 1000000000
ports:
- "8971:8971"
#- "8554:8554" # RTSP feeds

devices:
  - /dev/apex_0:/dev/apex_0 # passes a PCIe Coral
  - /dev/dri/renderD128:/dev/dri/renderD128  # For GPU acceleration
userns_mode: "host"

What I'm really looking for is some gidance on how to find more information to help me troubleshoot this. Are there any logs to help me, or a guide to help me figure out if I've missed some crucial step. I've found the Podman documentation to be somewhat elusive.