I have now tried to change the external URI to bpdehamlogcon01.mydomain.de and now getting a slightly different error. It seems to still cant call the API on the node but this time the reason is an unexprected end of stream on 10.28.6.108:443
Im still not sure why the server can’t reach itself
I also found an artical that might help SSL Issues ProxiedResource Unable to call Hostname not verified - Graylog Central (peer support) - Graylog Community
The User states to
6. Make sure you have the following. NOTE: IP Address is preferred in the certs that point to your Graylog server etc…
which sound like it might help, since my certs only know the Server name and not the IP. But i dont know how to do that