Reverse Proxy - OPDS issues

I'm running Ubooquity 2.1.0 in a Docker container through an nginx reverse proxy. I can access the main page without issue, but cannot access the OPDS feeds without getting 405 error. I have tried Moon Reader and Comixology with the same results.

nginx conf is:

server {
        listen 443;
        server_name book.mysite.com;
        location /ubooquity/ {
                proxy_pass http://###.###.###.###:####;
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_connect_timeout 150;
                proxy_send_timeout 100;
                proxy_read_timeout 100;
                proxy_buffers 4 32k;
                client_max_body_size 8m;
                client_body_buffer_size 128k;
        }
}