Not all quests are mentioned in the Lorebook. Only the main quest chains are.
Those chains may have other quests as prerequisite.
Check your quest log in the main game window, if there are still quests to be done there, go through them.
This will eventually bring up the quest mentioned in the Lorebook or unlock it.
Should you not receive any new quests at all, contact Customer Support, and send screenshots of your main game window and your Lorebook.