Subdivide is messing up material ID

[Alexx31]

Hello,

when I subvdivide, then the material ID of the inner faces jumps at some particles also at the outer side.

How can I prevent that? 
Tried all settings in the subdiv operator.

(When breaking it should keep the main material outside of course.)

Thanks
   
   

[tyFlow]

I just use Max's own subdivide functions for that operator, so if issues like that are occurring, then it's a bug inside Max itself. Eventually I may rewrite the subdivide functions with my own.

[Alexx31]

Thanks for reply!
I will work around but can send you the file in case it's interesting.

[Alexx31]

Just wanted to mention, I had sent you the file and would be great if you could rewrite sometime. 
In my current project I was now able to use it with a workaround and subdividing helped getting a clear improvement.