NCPA uptime Check - urlopen Error

Hello Community,

I am currently blocked on my NCPA Check for the uptime of an Host. I couldnt find the problem. I hope together we can find a solution. Thank you in advance.

I am trying to monitor the uptime of a host with ncpa. The current situation is:
The check works for some hosts but not for the last host I want to check.
When I run the check manually it works fine. I get the result : ok - up for a couple of days. But not when I let icinga run the check automatically.
Icinga shows “unknown” use verbose flag as a problem - so I did include it in my automatic check and the output looks like this:

`Connecting to: https://xx.xxx.xxx.xxx:xxxx/api/system/uptime/?token=xxxxxxxx&warning=3600%3A&critical=300%3A&check=1

An error occurred:<urlopen error Tunnel connection failed: 403 Forbidden>`

I hope anyone has an idea what the problem could be.
thank you community.