I have a Miele W304 plus novotronic washing machine and the fabric conditioner does not flow through ,I have cleaned the 3 jets above the conditioner tray. I removed the tray and started machine to see if water flows out of jets it does but slow and not all 3 if I block 1 it comes out another. The drawer is clean.
Most Miele’s have a motorised diverter on top rear of the soap dispenser, the water is sent to the section required by the programme at that particular time, if its not moving or is sticking perhaps it’s not getting to conditioner section.
If its not got a diverter then i’d check inlet valve coil is not open circuit.