Hi Antonio,
3ds Max’s FBX exporter supports only the Standard (scanline) material type. If your model uses different material types, you have to convert the materials to Standard ones before the export.
Could you try using the “Reset pivot” button for the objects which are upside-down.
You can find more information about resolving these issues in:
https://help.shapespark.com/hc/en-us/articles/360009141717-Importing-a-3D-model-from-3ds-Max