[HELP] - ASUS RT-AC87U Media Bridge Issues

I'm having a slight issue with using my RT-AC87U in media bridge mode.

I am running the Asuswrt-merlin 384.11_2

I have changed the operation mode to media bridge and have been able to connect to the ISP router via wifi.
I have also been able to connect a device to LAN port 1, however devices plugged into LAN ports 2 to 4 are not being detected.

I have previously used this as my main router and had devices connected to all ports without any issues.

I have tried a factory reset but still...

[HELP] - ASUS RT-AC87U Media Bridge Issues