[4.19 ARKit] Reflection Capture Sphere and Metal Materials don't seem to work right

Testing out the AR template in 4.19 preview 5. I’m attempting to use IBL lighting by using an HDRI for both the skylight and the reflection capture probe. My diffuse materials properly respond to the skylight’s ambient lighting, but when I attempt metals, I get all black (indicating a failure to receive specular lighting from the reflection probe). I have the reflection source set to my cubemap, and the unreal preview window shows me great results. But when I deploy the AR scene to my iPhone X, all my metals are black (unlike the editor preview which shows correct).

Can anyone suggest or help me understand what might be going on here?

To test this out, simply create a new scene via the AR template, and create a “mirror” material:
------| Material Params:
–| White (3 vector constant) to diffuse
–| Metalness to 1
–| Roughness to 0

Assign that material to whatever geometry the scene contains (like the default cone/sphere static meshes the template is configured for).

Assign the default HDRI the engine uses to a sphere reflection capture, configure to use cubemap instead of “captured scene”.

Assign the HDRI to the skylight as well (although that doesn’t matter for a metal).

Deploy to iOS phone and see only black materials.

Suggestions anyone?

Is it possible that the reflection cubemap doesn’t fully wire into the lighting solution until you bake lighting? My actors are all moveable with zero environment (since this is AR), so I didn’t think I had to bake, but baking light looks like it fixed the reflection probes. Does this sound right?

I had the same problem in my AR-project (4.19 release) for iOS couple days ago. Yes, when you click Build button in editor reflection probes are updated as well. There is also separate menu item for it: Build -> Build Reflection Captures.

I have the same problem on android right now. Is there a solution for this?

edit: it works now. eventhough the scene is black with no mesh inside, lightbaking fixed it.