Observed with 'Add Annotation' intention, but may be common problem.
Open a source of library class, e.g. java.lang.String. Locate some method name like copyValueOf(char[]):String.
After a moment light bulb appears. Alt+Enter: intention menu opens. Ok.
Press Escape. Menu is hidden. Light bulb does not appear again. User has to move cursor to make it appear.
In project classes light bulb appears again after pressing Escape + a second. This checked with 'Add @Override annotation'.
Now in both project and library sources light bulb does not appear after escape until moving cursor. Looks like acceptable unification.