"The man drinks tea"
Translation:Ο άντρας πίνει τσάι
That's right, both spellings are fine (it's a bit like colour/color in English).
But the course should only teach one even if it accepts the other, so I've now tried to remove the άνδρας spelling from showing up as a "suggested" answer (e.g. "another correct solution" or an option in multiple choice) while retaining it as an accepted alternative.