Unable to access internet after setting up Network mode to "Router"

Hello,

Please find me configuration :
Model: GL-MT3000
Kenel version: 5.4.211
Network Mode: Router
Syymptoms :
I have a local network on which I do not have any issue from my local device to access internet, But I soon as I am connected via Wifi on the GL MT3000 Router I am not able to access internet.

Can you please help me (from what I understand the NAT setting are implicit on network mode "router".