HTTPCode 404 for HEAD requests, 200 for GET requests

[ivancarlosti]

I found a bug looking to monitor my URL

When I monitor my DDNS dashboard using HEAD it returns 404 (not found)
When I do the same using GET, it returns 200 (OK)

HEAD Request with basic auth by UptimeRobot

2024-10-02 16:41:35 | 216.144.248.29 - - [02/Oct/2024:19:41:35 +0000] "HEAD /admin/ 1.1" 404 0 "https://ddns.mydomain.com/admin/" "Mozilla/5.0+(compatible; UptimeRobot/2.0; http://www.uptimerobot.com/)"
-- | --

GET Request using basic auth by UptimeRobot

2024-10-02 16:46:20 | 216.144.248.29 - - [02/Oct/2024:19:46:20 +0000] "GET /admin/ 1.1" 200 1728 "https://ddns.mydomain.com/admin/" "Mozilla/5.0+(compatible; UptimeRobot/2.0; http://www.uptimerobot.com/)"
-- | --

The HEAD 404 happens after basic auth, if I do not send the basic auth it returns the 401 code as expected.

Could you please check why it returns 404 for HEAD requests?

Thanks a lot and regards