It is most likely that the rain sensor in this situation does not work because it is not fit to the glass, which in turn occurs when the sensor is malformed, is programmatically misconfigured, or when the lens is detached from the glass.
To correct the problem, check the glass to see if the sensor or lens was installed incorrectly when the glass was replaced. If the glass is good, you need to perform a secondary initialization of the sensor and clear all errors. Sometimes it does not help even re-initializing or replacing a sensor-in which case it is best to replace the entire glass.
