Thanks for your help. I’ll keep looking in the meantime.

I also found this information in another post;

alzhao Apr '16
The LAN LED is fixed as POWER in hardware. So it is always on.
The WAN LED and WiFi leds can be controlled.

Therefore, tested using another LED (If I am understanding the three LEDs)
echo 255 >/sys/class/leds/rt2800soc-phy0::assoc/subsystem/rt2800soc-phy0::quality/brightness

No change.