Hello dear! :)
For now, Coptic Christians that belong to the Oriental Orthodox family of Churches are not in full communion with the Eastern Orthodox Churches. The split between Oriental Christians and the rest of the Christendom (namely Eastern Orthodox and Catholics) dates from 451, were the political / ethnic factors were and remain very important in this tragic split.
In many countries, Oriental Orthodox Christians can receive communion in Eastern Orthodox Churches, but the clergy cannot concelebrate. A lot of work has been done through dialogue to heal this schism, and several agreements have been signed. But it is quite difficult to bring about a formal reunion because of the many practical problems, such as the anathemas (excommunications) pronounced in 451, the differences in the recognition of saints, the fact that two bishops occupy the same see in many places, etc. However, there is much progress and the dialogue was fruitful. It could be really awesome if union could happen in our lifetime, because it would be the first step in the unity of Christians. In my opinion, it may happen during my life, God willing, at least it’s much more realistic than union with Catholics or Protestants at the moment.
To the best of my knowledge, Coptic Orthodox Christians reject monophysitism as a grave heresy, so they are not Monophysites (Monophysitism is the Christological -and heretical- position that, after the union of the divine and the human in the historical Incarnation, Jesus Christ, as the incarnation of the eternal Son or Word of God, had only a single “nature” which was either divine or a synthesis of divine and human.). Today, it is recognized that the theology of both groups (Eastern and Oriental) is essentially the same and that the disagreement over the wording used at Chalcedon could be overcome.
For another time, I will say that though formally we are not in *full* communion yet, I do love my Coptic brothers and sisters and really admire them for their Christian witness in recent persecutions in Egypt and I do love their traditions. Personally I see them as Orthodox, but yet not in communion with my Church. May God bless them always, as well as my pious Catholic and Protestant brothers.
God bless you!