I've changed the password on the 902AC - it was the same!. It still won't connect on wifi, though. However the Livebox on 192.168.1.1 comes up while connected to Openwrt wifi.
then it probably connects, disconnect, and swaps over to your other wifi.
would be better if you changed the SSID altogether, so you know where you're connected.
you'd want that for your firestick and TV anyway, otherwise you won't know where they connect.
disable the main wifi, or force the computer to forget it.
sorry, but this is an os issue, not really openwrt.
OK thanks for your help, I've leaned a lot! Just a bit odd that 192.168.1.2 worked on wifi.