Nextcloud - internal server error

I start my nextcloud container with the following command on my Raspberry Pi 4:

docker run
–name nextcloud-io

-p 4431:443
-p 8081:80

-e PUID=1000
-e PGID=1001
-e TZ=Europe/Budapest
-e version=docker

-v /home/pi/docker-data/nextcloud-io:/config
-v /mnt:/mnt
-v /home:/home
-v /srv:/srv

–restart unless-stopped

I set up nextcloud, everything works.
I restart the container, everything works.

I remove the container and recreate it with the same above command, an internal server error message appears and there is no way to fix it.

Internal Server Error
The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

/config/logs/nginx/error.log is empty.

/config folder is still the same, it is full with the originally created files with all the original permissions.

I found the problem: I forgot to map the /data folder (I thought it was for something I don’t need).
A simple restart kept the automatically created volume, but a remove-recreate unlinked it and created an empty one. This broke the system.

I’ve binded it to a folder and it works.

-v /home/pi/docker-data/nextcloud-io-data:/data \

Thanks a lot!