USD import not showing up

Exploring the USD file format. Made a simple scene in 3dsMax 2024 with latest USD extension installed. Have different lights and materials to see which ones transfer best. Export a USD file with basic settings. But when I bring it into Unreal I see only a box. Have tried changing a couple settings here and there but nothing works. Any ideas???
Using Unreal 5.3
Thanks - Chris


Did you check that your lights are following the one supported by UE