Typical. I forgot to restart, it should be all good now :)

You may need to clear your cache for the new configuration to take effect, and any broken images will be fixed sequentially.

For anyone else who experiences this Server error.. In my case, I mistakenly thought pictrs ‘s docker container was fully stateless, when configured with object storage. Long story short, it isn’t. You should still mount the mnt directory as it contains db and metadata files.