No Firewalls available when creating SD-WAN Connection Group

I have two Sophos XG appliances running SFOSv18.5.1 MR-1. Both are being managed by Sophos Central and covered with Central Orchestration trial subscritpion. Unfortunately when I'm creating the SD-WAN Connection Group the Available Firewall column is empty and I can't assign any firewall. Please advise.



screenshots added
[edited by: MarekDalke at 10:27 AM (GMT -7) on 16 Jul 2021]