What are stories on awakening while practicing teaching the Dhamma?
One example comes from the Khemaka Sutta:

That is what Ven. Khemaka said. Gratified, the elder monks delighted
in his words. And while this explanation was being given, the minds of
sixty-some monks, through no clinging, were fully released from
fermentations — as was Ven. Khemaka's.

Before he taught them, Ven. Khemaka was not an arahant. But after he taught them, both he and his audience became arahants.