There is plenty of evidence for the existence of sola scriptura in church history … among heretics.
cin.org/users/jgallegos/sola_her.htm
That’s what strikes me as so odd about the notion of
sola scriptura in the first place. It arose many, many times over church history, and every single time, it was being asserted to defend heresy. The only times that the Early Church Fathers made statements that even resembled
sola scriptura were to demonstrate that the heretical doctrines would still be false even if the heretic’s false notion of
sola scriptura were accepted. Such presentations are often used by uninformed Protestants to say “see, St. X believed in
sola scriptura.” Of course, people making such an interpretation conveniently ignore two critical contextual factors: (1) this position (i.e., arguing from Scripture alone) was adopted solely for the sake of argument and solely in that instance, so it can’t possibly be used to prove a universal principle of authority like
sola scriptura, and (2) the Fathers making such arguments
invariably point out that it is
not necessary to rely on Scripture alone because Tradition and the ecumenical councils provide an equally true witness, directly contradicting the principle of
sola scriptura.
So to put in in a nutshell, there is an overwhelming amount of evidence about
sola scriptura in the Church Fathers, and that evidence unanimously condemns
sola scriptura as a feeble excuse for heretics to continue believe their heresies.