500 Internal Server Error nginx After update about btcpayserver-docker

[Delitants]

10-listen-on-ipv6-by-default.sh: info: /etc/nginx/conf.d/default.conf differs from the packaged version

docker exec -it nginx bash
cat /etc/nginx/conf.d/default.conf

server {
client_max_body_size 100M;
server_name btc.ott.blue;
listen 443 ssl ;
http2 on;
access_log /var/log/nginx/access.log vhost;
return 500;
ssl_certificate /etc/nginx/certs/default.crt;
ssl_certificate_key /etc/nginx/certs/default.key;
}

Cloudflare in use.

[Delitants]

LE certificate was 2 months past due, after recent update it started to show 500. Somehow few months it was OK with expired LE cert. LE is not updating not behind CloudFlare, nor without it.
Fixed 500 error by connecting a tunnel https://docs.btcpayserver.org/Docker/cloudflare-tunnel/