Key check always returns true

[Birman]

I've been working on a custom staff page layout and I noticed that there's a condition check for biography section. 

{{if \IPS\Member::loggedIn()->language()->checkKeyExists( "core_staff_directory_bio_{$user->id}" )}}
    <div class='ipsType_richText ipsType_normal' data-ipsTruncate data-ipsTruncate-size="4 lines" data-ipsTruncate-type="hide">{lang="core_staff_directory_bio_{$user->id}"}</div>
{{endif}}

The thing is that this checkKeyExists always returns true, regardless whether the bio exists or not. The logic behind this block here seems to be that it won't add any HTML elements between the if condition brackets unless biography is set. Am I wrong or is something else going on here?