I’m not sure that was the consensus, but I would agree the implementation of Main/Nodes with 3006/3004 is different (limited?) vs 3004/3004 (which is also limited) as opposed to how it should work, and does, with 3006/3006.
I’m not sure this is something
@RMerlin can fix for you though, I believe it’s all down to Asus i.e. I’m almost certain
@RMerlin cannot fix it in this or any other firmware, unfortunately.
So the options are I guess reverting to HW that can do 3004/3004, living with 3006/3004 implementation, upgrading to the all singing all dancing 3006/3006 (or 3006/3006VLAN) option or… bailing out and moving to a different manufacturer.