That information only appears on the 2nd edition rulebook, under the navigator career, and nowhere else. Ironically, on the 1st edition rulebook, the compass was listed as one of navigator trappings (pg 102):
The Navigator is a vital member of a ship's crew, responsible for charting and setting courses and making sure that the ship is where it should be and headed in the right direction. Navigators can set a course by the stars, by the sun, or by using charts. Their navigational skills are equally useful on land and Navigators may sometimes be employed by expeditions or merchant ventures going into unknown territory.
Trappings: Navigator's instruments (compass, sextant, etc.), 2D6 maps and charts, Hand Weapon, Mail Shirt
But again, that is the only mention of a compass in the book, and is probably talking about the other compass, a tool used to draw. However, they do mention compasses as references here and there, but not the actual item, like:
Four main gates allow pedestrians and horsemen into the city, one at each of the compass points.
Or even as the name of an inn:
The player characters start the adventure at the Shattered Compass, an inn near the waterfront in L’Anguille.
There are magical compasses in the setting that point at different things, like the Compass of Meteoric Silver:
Leonardo has a special compass with a direction arrow made from meteoric silver. This will point to the greatest concentration of magic on the battlefield.
But considering they say it's a special compass, maybe there are not-so-special compasses too. Regardless, it seems that there are no compasses in Warhammer Fantasy setting due to omission, and not because of some mysterious force.
My search encompassed (and they love using that word) the following books, in no particular order, I went back and forth looking under different terms: 1st and 2ed edition core rulebooks, Fantasy Companion, Career Compendium, Tome of Corruption, Tome of Salvation, Karak Azgal, Barony of the Damned, Old World Bestiary, Old World Armory, Realms of Sorcery, Realm of the Ice Queen, The Thousand Throne, Plundered Vaults, Shades of the Empire, Renegade Crowns, Lure of the Lich Lord, Night's Dark Masters, Terror in Talabheim, Knights of the Grail, and I could be forgetting another book, but that was mostly it.