Why does a cavity disappear when it is placed very close to another cavity?

Why does a cavity disappear when it is placed very close to another cavity?

If any point of the cavity being inserted lies exactly on the Periphery of Step 0 of an adjacent cavity, then the newly inserted cavity disappears from display. This is a limitation of SOLIDWORKS .

In such cases, the affected cavity may be deleted from the cavity browser and reinserted at a new location slightly offset from the original.