IntelliJ IDEA doesn't recognize exceptions down the inheritance tree

Suppose I have some `ParentException`

public ParentException extends RuntimeException {}

and also some `ChildException`

public ChildException extends ParentException {}

In that case, IntelliJ IDEA doesn't always recognize `ChildException` as an exception. That is, I don't see the lightning icon. Perhaps, the issue doesn't have to do with inheritance. At any rate, the icons sometimes don't appear for my custom exceptions (and sometimes they do)