Normal for PVA. The sharp vinegary note is residual acetic acid off-gassing and it usually fades over one to three weeks depending on how thick you went and how much air it gets. Stand the book on its fore-edge with the boards fanned slightly open somewhere with airflow and it clears faster.
What isn't normal is musty or bready. If it smells sour-sweet like old dough rather than sour-sharp like vinegar, that's the wheat paste going off and it only gets worse.