My cloudflare reverse proxy stopped working after switching ISPs

[spiderdan19]

What is the name of the domain?

welovegladstone.com

What is the error number?

521

What is the error message?

The web server is not returning a connection. As a result, the web page is not displaying

What is the issue you’re encountering

I moved my web server to a new ISP (from BT to Virgin Media). The web server was working perfectly fine before with BT. But with Virgin Media it has completely broke with it only producing error 521 and 522.

What steps have you taken to resolve the issue?

Turned off the router firewall,
Redid my nginx config with the new local IPs and ports,
Gave it time to see if the issue would resolve by itself,
Asked for help elsewhere.

What feature, service or problem is this related to?

DNS not responding/updating

What are the steps to reproduce the issue?

Setup a reverse proxy under Virgin Media.

Screenshot of the error

[Laudian]

Have you checked that it works in DNS-Only mode?

[spiderdan19]

I haven’t no, but I did notice when I changed my SSL settings to flexible. It suddenly was able to redirect to my server (albeit not the docker container I directed it to).

[Laudian]

Flexible uses port 80, so it seems you have not configured forwarding or your firewall correctly for port 443.

Flexible disables encryption, so you should not use it for more than debugging.