OpenWRT WiFi Client Bridge - No Internet on LAN Devices

[DoSpamu]

Body:

I have a setup with two routers running OpenWRT:

Main router (AX3600):
    IP: 192.168.1.1
    DHCP server enabled, handles DNS and gateway.

Secondary router (Archer C6 v2):
    Goal: Connect to the main router as a WiFi client and bridge LAN devices to the main network.

Here’s what I’ve done so far on the secondary router:

Set br-lan interface to:
    IP: 192.168.2.1
    Disabled DHCP.
    Set gateway and DNS to 192.168.1.1.

Removed the default WAN firewall zone.

Connected to my main router's SSID in WiFi client mode.
    Attached wwan to the lan interface group in Network > Interfaces.

Configured wwan interface:
    Static IP: 192.168.1.110 (from the main router's DHCP range).
    DNS and Gateway: 192.168.1.1.

Installed the relayd package and configured a bridge:
    Bridged wwan (WiFi client) and lan (LAN ports).
    Set the local IPv4 address in the relay bridge to 192.168.1.110.

What works:

The secondary router itself has internet access.
    Pings from Diagnostics work.
    The wwan interface gets an IP (192.168.1.110) from the main router and shows up in its client list.

The Problem:

LAN devices connected to the secondary router don’t get an IP address from the main router’s DHCP server.
Sometimes a LAN device gets an IP (e.g., 192.168.1.202), and it shows up in the main router’s client list, but there’s still no internet access on the LAN device.

Hardware and Versions:

Main Router: AX3600 running OpenWRT 23.05.0
Secondary Router: Archer C6 v2 running OpenWRT 23.05.0

Questions:

Could the main router be blocking DHCP requests or not forwarding packets properly?
Did I misconfigure relayd or miss a critical step?
Is there a better way to achieve this setup?

Any help would be greatly appreciated!

[DoSpamu]

Summary of What I Did and My Current Setup

The main router (192.168.1.1) is connected to my ISP. It acts as an access point, handles DHCP, etc.
The secondary router, which is the focus here, was supposed to work as a Wi-Fi adapter to provide internet for two desktop PCs—a bridge client for the main router.

Initially, I tried using the relayd module (OpenWRT relayd configuration guide), but it didn’t always work. It seemed to have compatibility issues and failed to provide internet to the end devices consistently.

Finally, I set up the router as a WDS client (OpenWRT WDS guide), and everything worked perfectly right away.

Final Configuration of the Secondary Router:

• Connected to the main router as a WDS client, obtaining an IP address via DHCP.
• The br-lan bridge is set to static with the IP address 192.168.1.2.
• DHCP is disabled, with the gateway and DNS set to 192.168.1.1.
• Removed the WAN rule from the firewall.
• Added the wwan interface to br-lan to ensure it has internet access.

---