importing FBX into Unreal Engine — it doesn't recognize the metallic map, and instead it connects the roughness map to the metallic input

[onion-bomb]

In Blender, all my materials are set up correctly with separate maps for metallic and roughness. But when I import the FBX into Unreal Engine, it doesn’t detect the metallic map and ends up connecting the roughness texture to the metallic input. How can I fix this?