I moved my headless server to a different site.
I use curl to call IP Update from this server, but it returns 'nochg'.
When I try 'echo url="https://api.dynu.com/nic/update" | curl -k -K -' it returns 'unknown' (for the actual updates, I include parameters hostname, username and password).
In a browser on my laptop 'https://api.dynu.com/nic/update' also returns 'unknown', for this site.
However, when I'm in my Control Panel at www.dynu.com, it shows my external ip.
The call 'curl 'https://api.ipify.org?format=json'' also returns my public ip (same as shown in dynu control panel).

Do you know why the call to 'https://api.dynu.com/nic/update' can show unknown, while the dynu control panel shows my external ip address?
Do you know actions I can take to get the IP Update working?