Wlan Ethernet Bridge to Wan Raspberry Pi3B

Hi folks,

I am experimenting with LEDE by setting up a router/gateway using a spare Raspberry Pi 3B. So far I have setup a WLAN AP at wlan0 and have ethernet at eth0. I then set a bridge between the two interfaces at br-lan. I also hooked up my LTE modem using mbim and connected to WAN at wwan0.

I can access the internet from the raspberry pi however any devices connected to the bridge br-lan can't access the internet.

What do I have to do to allow devices connected at br-lan to access internet via wwan0?

Any help would be appreciated, thanks.

I seem to remember that 4addr could be one of the things that don't work with brcmfmac, but I may be wrong (don't have any device using it myself).

iw list on the RasPi returns the following:
Supported interface modes:

I noticed there is no WDS mode. But isn't it used to bridge access points? My setup has one wireless AP at wlan0.