SSL issues at installation


I’m trying to install Collabora CODE on my server which is running Debian Buster 10. I’m using an Nginx reverse proxy. When I try to navigate with the browser to I get a 404 from Nginx and when I navigate to I get the default “Welcome to Nginx!” page. journalctl -u -f loolwsd doesn’t show anything when I do it.
I’ve followed the instructions for the Nginx config here terminating at the reverse proxy. Correct me if I’m wrong, but the risk of terminating at the proxy is minimal since Collabora should not be exposed towards the outside. Alternatively, would a self-signed certificated between Collabora and Nginx be a good idea?
I modified the enable and termination settings in the ssl tag in the loolwsd.xml file.
I’m using Pydio Cells as well, and when I try to open a document from there with SSL enabled, journalctl -u -f loolwsd writes
WRN client - server version mismatch, disabling browser cache.
ERR Looks like SSL/TLS traffic on plain http port

Does anyone have any ideas who can I solve this problem?