The ECFs are in varied opinions on the issue of transubstantiation as you are aware.
I did find this brief history of transubstantiation:
The doctrine of transubstantiation is the result of a theological dispute started in the 11th century, when Berengar of Tours denied that any material change in the elements was needed to explain the Eucharistic Presence, thereby provoking a considerable stir.[22] Berengar's position was never diametrically opposed to that of his critics, and he was probably never excommunicated, but the controversies that he aroused (see Stercoranism) forced people to clarify the doctrine of the Eucharist.[23] The earliest known use of the term "transubstantiation" to describe the change from bread and wine to body and blood of Christ in the Eucharist was by Hildebert de Lavardin, Archbishop of Tours, in the 11th century.[24] By the end of the 12th century the term was in widespread use.[22]
The Fourth Council of the Lateran in 1215 spoke of the bread and wine as "transubstantiated" into the body and blood of Christ: "His body and blood are truly contained in the sacrament of the altar under the forms of bread and wine, the bread and wine having been transubstantiated, by God's power, into his body and blood".[25] It was only later in the 13th century that Aristotelian metaphysics was accepted and a philosophical elaboration in line with that metaphysics was developed, which found classic formulation in the teaching of Thomas Aquinas."[22]
In 1551, the Council of Trent confirmed the doctrine of transubstantiation as Catholic dogma, stating that "by the consecration of the bread and wine there takes place a change of the whole substance of the bread into the substance of the body of Christ our Lord and of the whole substance of the wine into the substance of his blood. This change the holy Catholic Church has fittingly and properly called transubstantiation."[34]
In its 13th session ending 11 October 1551, the Council defined transubstantiation as "that wonderful and singular conversion of the whole substance of the bread into the Body, and of the whole substance of the wine into the Blood – the species only of the bread and wine remaining – which conversion indeed the Catholic Church most aptly calls Transubstantiation".[34] This council officially approved use of the term "transubstantiation" to express the Catholic Church's teaching on the subject of the conversion of the bread and wine into the body and blood of Christ in the Eucharist, with the aim of safeguarding Christ's presence as a literal truth, while emphasizing the fact that there is no change in the empirical appearances of the bread and wine.[35] It did not however impose the Aristotelian theory of substance and accidents: it spoke only of the species (the appearances), not the philosophical term "accidents", and the word "substance" was in ecclesiastical use for many centuries before Aristotelian philosophy was adopted in the West,[36] as shown for instance by its use in the Nicene Creed which speaks of Christ having the same "οὐσία" (Greek) or "substantia" (Latin) as the Father.
https://en.wikipedia.org/wiki/Transubstantiation
I did not need you to reproduce the Wikipedia article on transubstantiation. It is related to, but not the same as, Eucharistic Realism, i.e. the firm conviction, based on the very words of Jesus Christ, that the Eucharist is His True Body and Blood. This was the continuous belief of Christians for centuries before the technical term "transubstantiation" was adopted, and for 1500+ before the ancient doctrine was rejected altogether by the Protestant new paradigm.
But I didn't ask you about "transubstantiation." I asked you:
Ears perked. I am sincerely interested. I am here to learn.
From the (Greek) Liturgy of St. John Chrysostom Byzantine-Ruthenian usage::
May the partaking of Your Holy Mysteries, O Lord, be not for my judgment or condemnation, but for the healing of my soul and body.
O Lord, I also believe and profess that this, which I am about to receive, is truly Your most precious body and Your life-giving blood, which, I pray, make me worthy to receive for the remission of all my sins and for life everlasting.
Amen.
Both the Latin "transubstantiation" and the Greek "metaousiosis" indicate Eucharistic Realism.
I'm not going to footnote this, but you should be able to google it instantly with those two keywords.
Have you found anybody prior to the 16th century who claimed the Mass was contradicted by the NT? For instance, has anybody said the Mass contradicts John 6:55?