I just had a quick look at the font settings.
Helvetica Neue Light was used—which is activated as a standard font with my OSX. Then I tested different fonts by changing it in the Alfred preferences. But whatever font it was, it still showed the missing glyph sign. However, if I check the bar glyph in FontExplorer (alt+7), it shows correctly with every any font.
I'm puzzled...
Note:
||| Being a graphic designer, I use the arcane glyph constantly |||