[NoCatNet] Multi-hop authentication

[van]

I've got my authentication server working good by using nocatsplash.
But there is one problem.
When I plugged my mesh node to the gateway (for now is a computer) by ethernet cable, the clients connected to the AP interface of this mesh node can access external network.
Clients---------------------------mesh_box1------gateway--------external_network
-----------------------------------------------------------------|
--------------------------------------------------------------auth_server
When I have another mesh node connect wirelessly (mesh interfaces) to the first mesh node before going through the gateway, the clients connect to the AP of the second mesh box cannot get the log-in screen hence cannot access external network.
Clients------mesh_box2------mesh_box1------gateway--------external_network
-----------------------------------------------------------------|
--------------------------------------------------------------auth_server

I think there is a parameter that I need to change in order for it to work but I have no clue.
Please give me some advice.