Title Studio - Ambient light issue

I’m not sure whether this is a bug or expected behaviour, so I’m throwing this out here for any comments before I log it as a bug.
Create any flat object, text or spline.
In the Camera/Lights section, turn any configured lights off. Turn Ambient to 100. Object is illuminated.
Change the object into an extrusion. The object is not illuminated, despite the ambient setting of 100.
Ambient light is omni-directional, so all parts of the extrusion should be illuminated, leaving no shadows.
I can’t imagine that’s expected behaviour.

EDIT - Problem solved. I misunderstood the behaviour of the Ambient intensity value. This value mixes the ‘Ambient Color’ with the object’s Ambient colour in its ‘Material Attributes’ tab. As this colour is black by default, mixing it with white, or indeed any other colour, will result in black (if I’m remembering colour theory correctly), irrespective of the ‘Ambient’ intensity value in the Lights tab.
On the other hand, if the object is not an extrusion, it doesn’t have an Ambient colour assigned to it. So, providing its ‘Fill Color’ is white (default), its colour and intensity will be the ‘Ambient Colour’ and ‘Ambient’ intensity value in the Lights tab.
I can now see that what’s happening is indeed, expected behaviour.

Unfortunately, I can’t mark my own comment as a solution. Is it possible for someone else to do that for me?