Responsive images do not load

Hello to all,

I installed my Ghost but I have a problem, the images don’t load, it concerns the “responsive” images apparently, with the URL “[…]/content/images/size/w2000/[…]”, when I copy and paste the direct link of the image that doesn’t load, I get the error "We’ll be right back. Here are the technical details of my installation:

Ghost is installed on my machine with the official Docker image, the database used is SQL Lite
The Docker container is accessible via a NGINX reverse proxy. The whole thing is on the domain which is a DNS entry managed by Cloudflare with the cloudflare proxy disabled for the blog.
Example with the image:
Direct Link: (Today’s update 8:30 UTC+1: The image now returns a 502 bad gateway)
Responsive Link: (This link does not work and is the one used for the article covers)
Does anyone have a solution?