Evidentially so: not a single codex survived in complete form; scholars disagree on whether some passages, such as the Adulteress Pericope, are genuine.
The Church, however, the pillar and ground of truth, is doing just fine, by Divine design.
Of course not. There was no codex, only individual components of the canon of books, which the Holy Ghost was able to preserve as enumerated through the early discussions. And which we still have, through the copies made of the valid ones as the originals wore our and were carefully replaced. Without a doubt, Jerome had his place in making a Latin translation from the original languages, but at circa 400 AD, we have no assurance that he had "better" copies than we do now. In fact, they cannot be "better"--they can only be the same as we have. There is no "better."
And we have access now to some 5,000+ full or partial fragments, of which the oldest must be discounted not that they are "better" because they are old, but actually poorer because they survived only because they were infrequently accessed, and only because they were curiosities--not useful for study as reliable documents. And please, don't pester me with either "lower" or "higher" criticism. Let me stop that right here. If any one, it is Erasmus that showed good judgment, in that he did preserve and retranslate back to the Koine the segment Known as "The Johannine Comma," as well as the segment you mention, also in the writings of John.
Erasmus was furious about abuses of the Roman church system, through his understanding of the Koine; but he failed to place the church as necessarily subservient to Scripture as the sole standard for doctrine, as did Luther. And as do I, firmly and finally--and correctly.
The Church, however, the pillar and ground of truth, is doing just fine, by Divine design.
So you believe, and in a false interpretation of the Scripture you misuse; for if the Scripture were not preeminent, the church would be whatever you wanted it to be (as you are mistakenly defining the church's role); rather than the supporting structure for maintaining the superiority of the Word of The God, Who holds it to be even above His Name:
Psa 138:2 I will worship toward thy holy temple, and praise thy name for thy lovingkindness and for thy truth: for thou hast magnified thy word above all thy name.
In my estimate, the RCC is not doing fine, in that it sets itself above instruction by the Word of The Very Head of the Scriptural church, the Word Enfleshed, the Only Begotten-in-the-flesh Son of The God, The Lord Jesus Christ, and the Holy Scriptures the boundary of spiritual knowledge exclusive of tradition beyond the original eleven Apostles and Paul contained in its pages.
The psalmist said (as do I) speaking by the Holy Ghost:
Psa 130:5 I wait for the LORD, my soul doth wait, and in his word do I hope.
It doesn't say here that my hope is in a church, especially one that explicitly sets itself above His Word and clearly does not obey it in every respect, that does not accept that He has preserved it for use by every independent, autonomous, meek, obedient assembly on earth, as well as the invisible (to us now) paneguria (conference) and First-born's Ekklesia (convening body), whose names are written in Heaven:
Psa 12:6 The words of the LORD are pure words: as silver tried in a furnace of earth, purified seven times. Thou shalt keep them, O LORD, thou shalt preserve them from this generation for ever.
For, about preservation, not just of His Word, but of His words by Jehovah as well as His manifestation as Jesus, even the spelling and punctuation He affirmed, both in Koine as well as Hebrew:
Mat 5:18 For verily I say unto you, Till heaven and earth pass, one jot (jodh,Hebrew's smallest consonant; iota, transliterated in Greek) or one tittle (keraia--the period--in Greek, chireq in Hebrew, a dot, smallest vowel or vowel pointing) shall in no wise pass from the law (Hebrew/Aramaic in OT, Koine in NT) till all be fulfilled.
THE Bible interprets itself, and neither the RCC nor any other fallible human organization has authority to translate or interpret it beyond a literal, grammatical, historical, and cultural hermeneutic, nor to apply it in a mode foreign to the obvious intent of its Maker.
The christ and gospel of the RCC do not agree with the plain intent of the preserved and correctly interpreted Bibles I have. There is no earthly-ruled assembly of Christians than the local independent, autonomous, immersionist assembly maintaining the Gospel through obedience to Christ's ordinances, strong preaching of Christ and Him crucufued, and church discipline, in my Bible. There are no longer any supernumeraries ruling over churches other than their own local one. Uniform understanding of the Bible by The Bible produces unity in the Spirit of correctly in-doctrine-ated members, ones taught to question any teaching by searching the Scriptures for conformation to the determined Will of The God. No global super-rule is required nor desired.
A local church may be a pillar and a support basis for God's plan, but Jesus Christ is the Lord-architect, and through His Word and the unity of the members, tells the church what to do, AFIK.