Question Reflection probe confusion: metallic objects don't appear when baking?

I'm a bit confused about how to get fully metallic objects to appear in a reflection probe.

As an example, here's a a bit of a big spherical room, which has a very bright light source in the middle, for testing. In this version, the triangular panels are set to be non-metal:



If I bake a reflection probe, it picks up the lighting on the panels:





However, here's the same thing is I set the triangle panels to be metallic:



They show up fine normally, but the reflection probe bake causes the metal to be completely black in the probe:



The only thing I changed between the two is the "Metallic" slider of the panel material.

The spherical object is set Static for everything, and it's appearing in the reflection probe. Only it's black. What's the trick to getting metallic objects to appear lit in a reflection probe? Why does the probe not see the object the same way that the scene view shows it?