Both the Copts and the Greeks accept the Council of Ephesus of 431 that condemned Nestorius. The great theological hero of the Copts is St Cyrill, Nestorius' arch-enemy.
For a recent, very detailed discussion of why Nestorius' theology is heretical from an Orthodox Christian perspective and not simply 'misunderstood', see John Behr's book
The Case against Diodore and Theodore. —
Samn 55 mins ago