Java reflection - identify method return type

I am having a use case to identify the return type of a method is of List type or not. To check the return type, I am using Class#isAssignable method and came across this behavior.

public class ObjectReturnType {
    public static void main(String[] args) throws NoSuchMethodException {
        Method method1 = ObjectReturnType.class.getDeclaredMethod("objectReturnType");
        Class<? extends Object> returnType1 = method1.getReturnType();
        if (returnType1.isAssignableFrom(List.class)) {
            System.out.println("Yes it is.");
        }

        Method declaredMethod2 = ObjectReturnType.class.getDeclaredMethod("listReturnType");
        Class<? extends Object> returnType2 = declaredMethod2.getReturnType();
        if (returnType2.isAssignableFrom(List.class)) {
            System.out.println("Yes it is.");
        }

    }

    public Object objectReturnType() {
        return null;
    }

    public List<String> listReturnType() {
        return List.of("");
    }
}

Both methods are going through the if condition, I was expecting only the listReturnType method to go through the if condition, not sure why the objectReturnType method is going the if condition. Can someone help me to understand this behavior?