Please enable the Import of Multi/Sub-object Materials in Maya.
It's the main reason, why many 3ds Max shaders are not compatible.
And it's for sure no "rocket science" to set up a simple Material ID system (with Attributes) in Maya and provide a "Multi/Sub-Object material".
Please vote also here on Maya side:
https://forums.autodesk.com/t5/maya-ideas/multi-sub-object-material-amp-material-id-s-also-for-3dsma...