Skeletal mesh switches from smooth shading to flat after packaging UE5 project

[Little_Bunny]

Hello

We have a skeletal mesh that looks fine when viewed locally in UE5, however after the project is built, the polys are all flat-shaded and visible instead of looking smooth like they do in the original project. Here are images of the mesh in the local project vs the packaged build:

Any ideas what’s causing this?

Thanks