I just had the same issue happen to me as well. The Multi material seems to not be applied to the group of the reduced geometry model. I will send file along.
That would be easier but I want the billboard cross and Transmutr does it for me instead of going in and fitting it myself. I don’t know of any other way.
Unfortunately, I went away on vacation and while I was away, they upgraded my machine to win10. So I am still trying to find everything that was wiped. I don’t remember which file I used for this. I did just give it a try on a couple of FBX files and it seems to be working fine - maybe it was an isolated issue or fixed by the new hotfix1 that was put out by Chaos?