pfBlockerNG-devel sync doesn't start

Hi all
I have a pfSense 2.6.0-RELEASE wit h an installed pfBlockerNG-devel, Version 3.1.0_1.
To synchronise the pfBlockerNG-devel settings to another pfSense on the same version I thought to use the sync Option in pfBlocker, but it looks like the sync even doesn’t start on the source box. No entry in the pfBlockerng Log ist available to see if it starts and if there are possible issues.
I used https, LAN Port IP, Port 443, the Password from the Target Username is also working, I checked this several times.
Ping and port checks in both directions are working.
What else do I need to configure to get this working?

The XMLRPC Sync Settings are for HA setups, I don’t know if it can be used to sync settings in any other way.