NPM passes through some requests even though 444 option is set

[ericswpark]

Checklist

• Have you pulled and found the error with jc21/nginx-proxy-manager:latest docker image?
  • Yes
• Are you sure you're not using someone else's docker image?
  • Yes
• Have you searched for similar issues (both open and closed)?
  • Yes

Describe the bug

When running NPM with the default page option set to 444 (No Response), some requests still make it to proxied hosts, causing errors because the wrong HTTP_HOST is set (the server IP instead of the proxy hostname).

Nginx Proxy Manager Version

v2.11.1

To Reproduce
Steps to reproduce the behavior:

1. Set up a proxy host
2. Set default server behavior to 444
3. Send requests to the server IP

Expected behavior

None of the requests should make it through to the proxied host

Additional context

This issue appears to be sporadic as I'm unable to reproduce it on-demand. However, I get errors from the proxied app behind NPM, telling me that requests are coming through with the HTTP_HOST header set to the server's IP address instead of the correct hostname I set while setting up the proxy host in NPM.

[h4de5]

are those requests maybe related to static assets like .jpg, .css, .js or .woff files?

if so, there is a location rule in a include/assets.conf that takes precedence here.

[ericswpark]

@h4de5 nope, root (/) with no files.