Can't install Collabora Office on Synology with Docker

Hi guys,
I’m currently running a docker container for my instance of Nextcloud and it works really great so far.
It uses the nextcloud::fpm image in combination with a nginx webserver and the reverse proxy from my Synology Diskstation for the SSL stuff (Let’s Encrypt).
I mostly followed the guide on the Docker-Hub page for the installation.

Now i decided that it would be great to edit office documents in the nextcloud, so i tried downloading the OnlyOffice docker script, but it says that my OS is not supported.
So i switched to Collabora Code and started the container using this command:
docker run -t -d -p 127.0.0.1:9980:9980 -e 'domain=nc\\.mydomain\\.synology\\.me extra_params=--o:ssl.enable=false' --restart always --cap-add=MKNOD collabora/code

It runs but the output from the logs is huuge, and i’m not sure if thats correct (i uploaded it, because it would be too big to post it here):
https://pste.eu/p/67oj.html

However, the container is not crashing so i’m not sure if this is the problem.
When execute curl -k 127.0.0.1:9980 it gives me this error:
curl: (56) Recv failure: Connection reset by peer
The firewall is open, but it shouldn’t be a problem, because i executed it from the same machine where the Collabora server runs.

This is my NGINX configuration file: https://paste.ubuntu.com/p/CdjyMP5MfC/
Maybe someone can hint me what i’m doing wrong here, i spent a really long time to find the error, but was not successful.

Nobody got an idea?