Connecting fan to normal 4 node switch without regulator support

I had connected my fan with a normal 4 node switch that I bought last year. I was using a normal regulator with it and it had been working well for the last one year but now I have noticed that I cannot use the fan at all. The relay doesnt click even when I turn it on from the app.
What could be the issue?

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We cannot think of a solution given the information provided.