Another thing to check is the value of “Contact Threshold” in the Blast panel. We’ve had 2 people get an extremely large value in there (not sure how yet). If that is a huge number it will prevent physics from reporting collisions for the body, so it won’t fracture. The value updates when you select a prim, so select the fractured mesh in the Viewport (not the Stage).
If the value is large, you can click “Reset All to Default” at the top of the panel and refracture the mesh and it should behave properly. Please let me know if that fixes it for you.