Hi,

Does this happen when the Billboard helper graphics is turned Off?

Also, it could be for example that the billboard is placed at a very wrong place or you receiving incorrect zoom values. And this is why you don't see the helper graphics around the talent, but only on the talent.
And make sure that the Unreal node in Aximmetry's Flow Editor is correctly connected with the camera compound.

You could try turning off Render To Depth:

This way there will be nothing rendered at the place of Billboard in Unreal.
By turning Allow Virtuals off, Aximmetry already renders the billboard instead of Unreal. However, the Render To Depth will still display the billboard inside Unreal so that various Unreal effects could use it.

Warmest regards,