The fix was quite simple. What you will notice is that I hadn't opened up the port 443 in docker so it was not being allowed through once the redirect happened.

Credit to: https with nginx and docker compose not working

services:
    homer:
        container_name: homer
        image: b4bz/homer:latest
        volumes:
          - './www/assets:/www/assets'
        environment:
          - INIT_ASSETS=0
          - PORT=8080
          - BASE_URL=/
        restart: unless-stopped
    
      nginx:
        image: nginx:latest
        container_name: nginx_container
        ports:
          - 80:80
          - 443:443 ****** -> This is the fix ******
        volumes:
          - './nginx.conf:/etc/nginx/nginx.conf'
          - './certs/:/etc/nginx/certs/'
        depends_on:
            - homer
        restart: unless-stopped