Multiply mix strength not working as expected in C4D shader channel

In Photoshop and other multilayer imaging software, the Multiply layer mode, multiplies the color of the layer with the result of the underlying layers. So red x grey = dark red, and red x black = black. White does not have any influence (red x white = red). So a red colour with a white to black gradient should result in a red to black gradient. This works the same in the C4D material channels.

Logically, when the Multiplication is less strong, the result should be less dark.

But in C4D something strange happens when the Strength of the Multiplication is lower than 100%. This gives a darker result; even black when the Strength is 0%. Does anyone know why this is?