Help with Wifi Client and Ethernet Bridge

Hi, I have just installed openWRT on my PicoStation M2 for a task where I need ethernet device to connect in a remote location.

I am trying to use the PicoStation to act as a WiFI Client, and then be able to use the ethernet port on the Pico to also share the wifi client network, giving me LAN access all the back to the main AP.

I would have thought this was as simple as bridging the 2 interfaces, but it seems to be tricky.

I am connecting the Pico to a Unifi AP, and have also tried in WDS mode, but when in WDS mode, it does not get a IP address from DHCP, only does when in plain Client mode.

Is there a way I achieve this?

Thanks