On the grand scale of things, it's a minor point-of-origin bug. The Heist board is the only one of the three in the Glenumbra den which is automatically unlocked if you have unlocked it in Hew's Bane. You can't take a Heist job in Glenumbra unless you've progressed Hew's Bane to the point where Fa'ren-dar is in the den, but you can take a Heist job in Glenumbra if you haven't yet done the Codex Caper, and that, too, may be a bug.

Also noteworthy is that Quen is instanced in the Daggerfall Outlaw Refuge until you complete her initial quest for Hew's Bane, so she's in the den after Codex Caper and also right by the Fence until Parners in Crime is completed.