Devona Ironforge should be selling the crafting essentials recipe books at the Ironforge Exchange nowdays, so if she does not sell your level 20 ones that would indeed be a bug worth /bug -ing. I know she sells essentials books for higher levels as I gained a few levels there myself last night. Make sure you weren't checking Jason Merrytoe instead though, he doesn't do recipe books.
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(DominoDev) Re:crafting trainers do not offer me level 20+ recipes
