The two differences are on the Assumption and the Immaculate Conception. While the Orthodox believe in the Assumption - the Dormition of the Theotokos is one of the Great Feasts of the Church - they don’t think that it needed to be infallibly dogmatized (or are upset with us for doing so without their (name removed by moderator)ut/permission depending on who you talk to).
They also don’t like the Immaculate Conception. While they hold that the Theotokos is sinless (she is called Panagia or All-Holy), they don’t necessarily subscribe that she was preserved from the sin of Adam. One of the primary difficulties is that we have misunderstandings between us as to what exactly Original Sin is and what it entails.
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