Just took a look, and you should be able to just drag different objectives from the Library into the "Cryptic Map" Box in the storyline. It doesn't even matter on what Cryptic Map they are.
So, you don't really "add" a specific Cryptic Map, you just add the box (as shown in your picture) and put every objective (on every cryptic map) you like into it. It works a bit like a placeholder. The map the player has to go to is simply determined by the lokation of the mission objectives.
Ah the map transition bug, yeah it's well known bug that's been around for quite a while, you can't transition between maps in preview mode so if you want to test map transitions you have to publish the mission.
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So, you don't really "add" a specific Cryptic Map, you just add the box (as shown in your picture) and put every objective (on every cryptic map) you like into it. It works a bit like a placeholder. The map the player has to go to is simply determined by the lokation of the mission objectives.