I attached the hip and bgeo file. I tried to select 1 piece from the fractured object then add 'rbdmaterialfaracture', but for some reason it's not working. Nothing fancy setting just default. I check there's no unshared edges but why the fracture fails ?

I tested using voronoi fracture and it works but this rbdmaterialfracture does not work.

I'm using 20.5.613

On the RBD Material Fracture SOP, play with the Fog Volume > Noise Type, Noise Frequency and Offset. That piece happens to be in a region where the default noise values seem to be 0 which ends up generating no fracture points.