The event object always returns null. For example in your code example for Blazor, the event defined as public event WeatherForecastDelegate OnWeatherForecastChanged; the event OnWeatherForecastChanged always returns null and the code breaks saying "System.NullReferenceException: 'Object reference not set to an instance of an object.'". This is only happening now. It used to work well before.
The event object always returns null. For example in your code example for Blazor, the event defined as public event WeatherForecastDelegate OnWeatherForecastChanged; the event OnWeatherForecastChanged always returns null and the code breaks saying "System.NullReferenceException: 'Object reference not set to an instance of an object.'". This is only happening now. It used to work well before.