Permission Error -run-script in duplicati

Hey, i use the duplicati docker image and i run it as root…
I know that running as root is not supportet, but the docs say:

“Ensure any volume directories on the host are owned by the same user you specify and any permissions issues will vanish like magic.”

BUT i cannot ensure that any volumes i want to backup are owned by the same user… i have a lot of docker services like nextcloud and mailcow, so this was never an option. The docs do not mention how to handle such a situation…

Here is my problem:
I want to run a script before and after, but i always get “Permission Denied” errors.
The scripts have 777 rights for now and are owned by root
I can run the scripts witch docker -exec -it …

The docker socket and docker itself are mounted in the compose file.

The fact that i am running the container as root and get these errors is clearly some strange behaviour.