The same Christians that the Catholic church persecuted.
That's a serious charge, and of course if it is true it must be backed up by serious evidence.
I had laid out briefly, above, the historic councils that codified the Canon of Scripture. We know the times and places of these Councils ---the Council of Rome (382), the Council of Hippo (393), Third and Fourth Councils of Carthage (397, 418)---and the names, too, of those who affirmed the Catholic canon as we know it today.
So, are you saying that it was some other group of Christians who were preserving the Bible? I would like to know more. Who were they? Are you thinking of the Montanists? Or the Assyrian Church of the East -- the Nestorians? Or the Persian Church, a dhimmi community under the Rashidun Caliphate? Or ... When did this ancient "Bible preserving" happen, apart from the Catholic Church? and where? Did they produce an official Canon, other than the one affirmed by the Councils above? And where are the ancient Bibles they preserved?
You can see I am eager to know more about your historic Bible sources.
Thank you.