Hello,
For some reason some BaseColor UDIMs are not loading properly only in iRay mode with OmniPBR, everything works fine in PathTrace and RTX, but in iRay only 1 UDIM is loaded and the rest of the model is dark grey. iRay load Base Color UDIM properly with OmniSurfaceMaterial, but not OmniPBR. On some models it works, on some not.