Icinga for Windows not able to transmit data

Hi everyone,
I would really appreciante your help in the following matter:
I am getting the below error whenever I try to connect a Windows server to Icinga using Icinga for Windows client. I have a rather complex setup, as I use an Icinga cluster with 2 cluster nodes, and Icinga “workers” (nodes that connect upstream to the cluster) in each location that we have worldwide.
This setup works great with NSClient++ but does not work with Icinga for Windows.

ERROR:
warning/ApiListener: No data received on new API connection from [::ffff:XX.XX.XX.XX]:61188 for identity ‘windowsserver’. Ensure that the remote endpoints are properly configured in a cluster setup.

Technical data:
Workers and Cluster nodes: icinga2 - The Icinga 2 network monitoring daemon (version: r2.13.1-1)
Platform: Debian GNU/Linux
Platform version: 9 (stretch)

Icinga Web 2 Version
2.9.5
PHP Version
7.0.33-0+deb9u12