The national churches of the Russian Orthodox and the Greek Orthodox hate the Roman Catholic Church. If one is on the ground in the Ukraine, or a Catholic in Russia, or a Catholic in Greece, or a Catholic visiting the Holy Land, one sees this hatred daily.
Recently, a friend of mine was in the Holy Land. She was in a pilgrimage with lit candles in the Church of the Sepulcher. An Orthodox nun came up and asked if the group was Catholic. When she said "yes", the nun blew out their candles.
Watch what happens in the Ukraine to the Catholics, the Uniate Byzantines who fled so long ago from the Russia invasion in 1919.
Do not be blinded by a media which does not understand the hand-in-glove relationship of church and state in Russia.