I suggest you look up Martin Jugie's masterful study: L'immaculee Conception dans l'Ecriture Sainte et dans la tradition orientale, Rome: Officium Libri Catholici, 1952, 489 pp.
The Eastern Orthodox (including Photius and Gregory Palamas) held generally to the belief in the Immaculate Conception of the Blessed Virgin from the ninth century until about the fifteenth. Afterwards, it became a disputed issue until the nineteenth century when the party opposing the doctrine won out.
Let every creature dance for joy. Let all the earth cry out and rejoice with exultation, that the medicine for the primal sorrow has just now sprouted, that, by the great solicitude of God for us, the destruction of the hereditary curse (THS PROGONIKHS ARAS) - in which the whole mortal race had sunk - is made present. And today, a heavenly gift such as this is asked for us, that not only that curse may be removed from us, but also that the whole nature be blessed for us, and that on the one hand that the partition-wall of ancient hatred may be abolished, and that on the other that the love of God be in the midst of men, and peace may rise.
Nicetas David Paphlago, Bishop of the Dadybrians in Paphlagonia (890-900 AD), Oration I - On the Natal Day of Saint Mary, Patrologiae Graecae vol. 105, col. 17B. My translation.
This was a different guy named Gregory Palamas (Patriarch of Constantinople from 1446 to 1452), not the Pillar of Orthodoxy. My apology for the confusion of names.