u didnt have to solder the wire optical to ur Pcb. the best options is use the both wires from imp -+v5 wire both into MC V5 spot with ur optical wire too and u should be fine. or wire from 360 pcb v5 and MC too into v5 spot and optical wire and u should be ok.
I know is one of those u need to do. After all u do have dual mod. So 360 and MM pcb’s need to be connected with Optical wire to work.