Can you tell me the model number of the appliance please
Have you removed the syphon part of the dispenser and cleaned the tube underneath it?
Then have you got a multimeter?
I would like you to test the inlet valve that delivers water to that particular compartment..
Below is a diagram of the inlet group.. You'll need to test the blue valve for its resistance. The resistance reading across the poles should be 3.7Ohms
Then I can only give you a diagnosis without tests...
Since you have thoroughly cleaned the dispenser and the syphon inside it, I can only assume 'without tests' that the appliance is not feeding the water through to the conditioning compartment on the appliance...
The water feed to the conditioning compartment is fed by a valve group which contains 3 valves of which I sent you an image earlier.. Without tests, I can only assume that the blue valve of the three has failed and is not supplying water to the compartment.
The Valve is part number L34C300I3 and is available here
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