The map is in Leng's room.
Located in the Adventurer guild, up the stairs, second door on the left It should be there on his desk, unless you've used a really outdated save, which can cause issues like that.
Try making a new game, jumping to act 2 and just play Lenya's story and see if you still have the same issue.
The next version after this one, has a new " jump to latest content option", so you can just select that choice and avoid playing the same content