How to display the "lost atoms“ in slab model

Hello, everybody
I constructed a slab model(it's based on an optimized supercell) with CASTEP in Materials Studio. However, the atoms in the slab model didn't display in the slab after optimized, while atoms did exist. So my question is how to display the "lost atoms" in the slab model.

Help would be appreciated.
Thanks in advance

Sincerely
Li