"This exile was the immediate cause of a long and deplorable schism between the Catholics of Antioch, henceforth divided into Meletians and Eustathians. The churches remaining in the hands of the Arians, Paulinus governed the Eustathians, while Flavius and Diodorus were the chiefs of the Meletian flock. In every family one child bore the name of Meletius, whose portrait was engraved on rings, reliefs, cups, and the walls of apartments. Meletius went into exile in the early part of the year 361. A few months later Emperor Constans died suddenly, and one of the first measures of his successor Julian was to revoke his predecessor’s decrees of banishment. Meletius quite probably returned at once to Antioch, but his position was a difficult one in presence of the Eustathians. The Council of Alexandria (362) tried to re-establish harmony and put an end to the schism, but failed. Both parties were steadfast in their claims, while the vehemence and injudiciousness of the orthodox mediator increased the dissension, and ruined all prospects of peace. Though the election of Meletius was beyond contestation, the hot-headed Lucifer Cagliari yielded to the solicitations of the opposing faction, and instead of temporizing and awaiting Meletius’s approaching return from exile, assisted by two confessors he hastily consecrated as Bishop of Antioch the Eustathian leader, Paulinus. This unwise measure was a great calamity, for it definitively established the schism. Meletius and his adherents were not responsible, and it is a peculiar injustice of history that this division should be known as the Meletian schism when the Eustathians or Paulinians were alone answerable for it. Meletius’s return soon followed, also the arrival of Eusebius of Vercelli, but he could accomplish nothing under the circumstances. The persecution of Emperor Julian, whose chief residence was Antioch, brought new vexations. Both factions of the orthodox party were equally harassed and tormented, and both bore bravely their trials.
Even at Rome and in the West, Basil and Meletius were to meet with disappointment. While they wrought persistently to restore peace, a new Antiochene community, declaring itself connected with Rome and Athanasius, increased the number of dissidents, aggravated the rivalry, and renewed the disputes. There were now three Antiochene churches that formally adopted the Nicene Creed. The generous scheme of Basil for appeasement and union had ended unfortunately, and to make matters worse, Evagrius, the chief promoter of the attempted reconciliation, once more joined the party of Paulinus. This important conversion won over to the intruders St. Jerome and Pope Damasus; the very next year, and without any declaration concerning the schism, the pope showed a decided preference for Paulinus, recognized him as bishop, greeted him as brother, and considered him papal legate in the East.
After many disheartening failures, there was finally a glimpse of hope. Two legates sent to Rome, Dorotheus and Sanctissimus, returned in the spring of 377, bringing with them cordial declarations which St. Basil instantly proceeded to publish everywhere. These declarations pronounced anathemas against Arius and the heresy of Apollinaris then spreading at Antioch, condemnations all the more timely, as theological excitement was then at its highest in Antioch, and was gradually reaching Palestine. St. Jerome entered into the conflict, perhaps without having a thorough knowledge of the situation. Rejecting Meletius, Vitalian, and Paulinus, he made a direct appeal to Pope Damasus in a letter still famous, but which the pope did not answer. Discontented, Jerome returned to Antioch, let himself be ordained presbyter by Paulinus, and became the echo of Paulinist imputations against Meletius and his following. In 378 Dorotheus and Sanctissimus returned from Rome, bearers of a formal condemnation of the errors pointed out by the Orientals; this decree definitively united the two halves of the Christian world. It seemed as though St. Basil was but waiting for this object of all his efforts, for he died 1 Jan., 379.
In 379 Meletius held a council of 150 bishops in order to assure the triumph of orthodoxy in the East, and published a profession of faith which was to meet the approval of the Council of Constantinople (382). The end of the schism was near at hand. Since the two factions which divided the Antiochene Church were orthodox there remained but to unite them actually, a difficult move, but easy when the death of either bishop made it possible for the survivor to exercise full authority without hurting pride or discipline. This solution Meletius recognized as early as 381, but his friendly and peace- making proposals were rejected by Paulinus who refused to come to any agreement or settlement. Meanwhile, a great council of Eastern bishops was convoked at Constantinople to appoint a bishop for the imperial city and to settle other ecclesiastical affairs.
In the absence of the Bishop of Alexandria, the presidency rightfully fell to the Bishop of Antioch, whom the Emperor Theodosius received with marked deference, nor was the imperial favour unprofitable to Meletius in his quality of president of the assembly. It began by electing Gregory of Nazianzus Bishop of Constantinople, and to the great satisfaction of the orthodox it was Meletius who enthroned him."
newadvent.org/cathen/10161b.htm
Sources
ALLARD, Julien l’Apostat (Paris, 1903); HEFELE, Histoire des conciles, ed. LECLERCQ, ii, 1; LOOFS in Realencyk. für prot. Theol. und Kirche, s.v.; CAVALLERA, Le schisme d’Antioche au IV et V siècle (Paris, 1905).
Ecclesiastical approbation. Nihil Obstat. October 1, 1911. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York.
"Chrysostom as lector and monk
It was a very decisive turning-point in the life of Chrysostom when he met one day (about 367)
the bishop Meletius. The earnest, mild, and winning character of this man captivated Chrysostom in such a measure that he soon began to withdraw from classical and profane studies and to devote himself to an ascetic and religious life. He studied Holy Scripture and frequented the sermons of Meletius. About three years later he received Holy Baptism and was ordained lector.
Chrysostom as deacon and priest at Antioch
As the sources of the life of Chrysostom give an incomplete chronology, we can but approximately determine the dates for this Antiochene period. Very probably in the beginning of 381 Meletius made him deacon, just before his own departure to Constantinople, where he died as president of the Second Ecumenical Council. The successor of Meletius was Flavian (concerning whose succession see F. Cavallera, “Le Schime d’Antioche”, Paris, 1905). Ties of sympathy and friendship connected Chrysostom with his new bishop."
This nex bishop was flavian, not in communion with Rome.
It goes on:
"St. Chrysostom as bishop of Constantinople
In the ordinary course of things Chrysostom might have become the successor of Flavian at Antioch. But on 27 September 397, Nectarius, Bishop of Constantinople, died. There was a general rivalry in the capital, openly or in secret, for the vacant see. After some months it was known, to the great disappointment of the competitors, that Emperor Areadius, at the suggestion of his minister Eutropius, had sent to the Prefect of Antioch to call John Chrysostom out of the town without the knowledge of the people, and to send him straight to Constantinople. In this sudden way Chrysostom was hurried to the capital, and ordained Bishop of Constantinople on 26 February, 398, in the presence of a great assembly of bishops, by Theophilus, Patriarch of Alexandria, who had been obliged to renounce the idea of securing the appointment of Isidore, his own candidate. The change for Chrysostom was as great as it was unexpected. His new position was not an easy one, placed as he was in the midst of an upstart metropolis, half Western, half Oriental, in the neighbourhood of a court in which luxury and intrigue always played the most prominent parts, and at the head of the clergy composed of most heterogeneous elements, and even (if not canonically, at least practically) at the head of the whole Byzantine episcopate. The first act of the new bishop was to bring about a reconciliation between Flavian and Rome. Constantinople itself soon began to feel the impulse of a new ecclesiastical life. "
newadvent.org/cathen/08452b.htm
Ecclesiastical approbation. Nihil Obstat. October 1, 1910. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York.
So, st Chrysostom helped to bring reunion between Flavian and Rome. But before that, he was under Flavian jurisdiction. Wich means that until he was made bishop of Constantinople, he was NOT united with Rome.
But i know you dont want to get confused with facts from your own encyclopedia, approved by your hierarchy.