selfhosted-traefik/nextcloud/README.md

There is also somwhere a step to set up an alias for occ that cam be used outside the container to directly execute the commands inside the container.

Check if you have to alter this line in the collabora/loolwsd.xml file:

<host desc="Regex pattern of hostname to allow or deny." allow="true">nextcloud\\.sporada\\.eu</host>