I opened a package (spec+body) from a DB, viewing the body.
Someone else changed the package code on the DB.
SQLNav will ask to reload the source from the DB, as it is changed, but it will only refresh the body, not the spec - until you view the spec, where SQLNav again will ask to reload the source from the DB (this time the spec only).
If the new code has additional functions/procedures that are published in the spec, they will show as “private” in the code explorer tab (until the spec is also reloaded).
If you were to view the spec whilst the code changed, the additional published functions/procedures will be marked in red after reloading the spec - as if they are not present in the body - until the body is reloaded, too.