Hi,

I'm not sure how you added the talent, but billboard components will not work effectively as they would require the LED Wall blueprint in Unreal to include billboard implementation. Instead, you should use the [Common_Studio]:Compounds\Keyers\Keyer__All.xcomp compound. This will allow you to integrate the keyed talent into your Unreal scene using a Get Aximmetry Video blueprint node. You can find more information about Get Aximmetry Video here: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/obtaining-graphics-and-virtual-assets/creating-content/creating-content-for-aximmetry-de/ue5-how-to-install-and-work-with-the-unreal-engine-based-de-edition/#get-aximmetry-video

If you really want billboard functionalities, such as virtual shadows (with some limitations), you can use Aximmetry to render the billboard using Aximmetry-specific camera compounds. For example, you could:

Note that I am using the AR Overlay input to place the billboard over Unreal's rendered picture. This means the Unreal scene will always be behind the billboard. If you want it to be part of the Unreal scene, you will need to use a Get Aximmetry Video blueprint node.
Additionally, you can add reflections of the billboard according to the Aximmetry SE documentation:  https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/obtaining-graphics-and-virtual-assets/creating-content/creating-content-in-aximmetry-se/planar-reflections/ 
And shadows: https://aximmetry.com/learn/virtual-production-workflow/preparation-of-the-production-environment-phase-i/obtaining-graphics-and-virtual-assets/creating-content/creating-content-in-aximmetry-se/augmented-reality/#adding-shadows

When using the AR Overlay, you have to turn on the AR Overlay to LED in the STUDIO panel of the LEDWALLS control board.
In the next version of Aximmetry, this option will be moved to a sperate panel, like below:

Warmest regards,