You should check the solders of the knob and see if there isn’t any broken connection there.
Sorry to read that you experience troubles.
Should the module be at the cause, please return it for inspection/repair/exchange.
Sorry for the inconvenience.
I have recently built another printer and indeed, the manual tells you to disconnect the heater plug. But if you do this, the menu doesn’t pop up anymore because of the temperature error. We’ll need to get this fixed in the manual.