When your site did not work properly in docker do following:

1. Check is nginx container running

docker ps -a

3fbec7a5431f        jwilder/nginx-proxy                                "/app/docker-entrypoi"   20 hours ago        Up 7 minutes                0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp   nginx-proxy

2. Check if it has proper configuration

docker exec nginx-proxy nginx -t

You should receive

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

docker exec nginx-proxy nginx -T

this shows configuration of nginx. So, no need to bash into nginx container and do cat /etc/nginx/conf.d/default.conf. It’s much faster.

3. Check if your container and nginx container has network connection.
   If not, connect them with

docker network connect mycontainer_default nginx-proxy

4. Check container logs

docker logs nginx-proxy -f --tail 250

That will show last 250 lines and continues to follow new data.