Here is the question and answer in the Ask an Apologist thread.
In the Byzantine Churches all Deacons are addressed as Father Deacon. All fully professed monks are also addressed as Father.
I know some of you might object to my repling to this but Fr Serpa did say, “Father” is reserved for priests in the Catholic Church.
That may be true in the Latin (Roman) Catholic Church but it is not true for the Catholic Churches of the Byzantine Rite.
Some places in the Byzantine Catholic Churches may have the same usage as the Latin Church, that is Father only for priests, but that is just one of the many latinizations. We are slowly removing these.