Hi there,
I’m somehow struggling to import Lightmap UVs from Blender. I’m using the FBX format. I tried all the “Lightmap UVs Source” options including “Generate”.
EDIT: Also tried OBJ and GLTF.
BTW found a small bug. If you reimport the model, the UV preview no longer works. You have to close and reopen the Model Window.
Thank you!