Wireless Connection - Nethserver

Please note I have a NS as my core device, ie as a firewall, mail server, DNS and DHCP etc, but i’m having trouble with connection my mobile connecting to the Wireless.
My setup is like this —–<TPLink Router (AP)><–Unmanage Switch>—
Laptops are wireless connected to TPLink Router (AP), but mobiles are connected to the Wireless AP but cannot open/display any of the pages.
Devices such as printers, laptops and PC are all user the NS IP as gateway. DHCP is disable on the TPLink Router (AP).
Can someone please assist.

Where in this scenario is your NethServer situated?
It looks like you configured your NethServer as Firewall. This means the server has at least 2 interfaces: 1 RED and 1 GREEN.
The logical way to go would be:

Internet - Modem - NethServer - switch - LAN with clients and AP

Can you provide a bit more info with used IP addresses/subnets?