With regards to the questionable nature of the council and its supposed authority; Apart from probable revocation of Photius’ excommunication, there is no evidence that Pope John ever assented to the content of the Photian synod of 879-880. He took no action, as far as the historical evidence shows from his numerous letters, against the addition of filioque to the Creed by Frankish clerics. He hardly can be said to have repudiated the Council of 869-870 as wrongfully condemning Photius; on the contrary, he had asked Photius to apologize for his past crimes. It is practically certain, from everything we know about John’s views on papal primacy (which show even in the edited letters accepted at the Photian synod) and his esteem for Nicholas, that he would not repudiate the previous council, and his ingratiating letter to Basil proves only that he was deceived as to the content of the Photian counter-synod.
There are no more references to Photius in the letters and decrees of Pope John. A late ninth-century compiler of the acts of the Eighth Ecumenical Council (869-70) tells the following story. When the Pope learned what really happened at the Photian synod, he sent the cleric Marinus to Constantinople to declare invalid what the legates had done. Marinus was mistreated and imprisoned for thirty days. Upon Marinus’ return to Rome, Pope John stood on the pulpit and anathematized Photius and anyone who supports him. Marinus renewed the anathema when he became Pope in 882.
In support of this story, we find that Pope Stephen V (VI) wrote to Emperor Basil in 885-886
that Photius was still trying to get the Council (of 869-70) abrogated. Naturally, this does not make sense if John had already abrogated it. We have already noted that it is implausible that John would nullify or repudiate the Council, but acknowledge that he may have at least ended the excommunication of Photius in the interests of peace.
On the contrary supposition that the popes from John VIII through Stephen V were on friendly terms with Photius, we have only the claims of Photius himself, a known prevaricator on such matters, as proved in earlier controversies. Yet the exact nature of papal attitudes toward Photius from 880 to 885 is uncertain.
Pope Stephen, for his part, certainly denied the legitimacy of Photius as patriarch. When explaining to Basil why he did not write about a recently assembled Constantinopolitan synod, Pope Stephen says:
"But to whom was the Roman Church to write? To the layman Photius? If you had a patriarch, our Church would often communicate with him by letter. But for our love for you, we should have been compelled to inflict on the prevaricator Photius more severe penalties than our predecessors have done.”
Basil was dead when this letter arrived, and the new emperor Leo VI used it as justification to depose Photius in 886.
Some of the anti-Photian bishops would not accept Leo’s new patriarch, Stephen, on account of the fact that he had been ordained by Photius. According to a Greek codex that includes Pope Stephen’s letter, Emperor Leo wrote to these anti-Photians, saying:
But if, seeing that he was ordained deacon by Photius, you would rather not communicate with him until you have consulted with the Romans who condemned Photius, let us write and ask the Pope to grant a dispensation from censures to those ordained by Photius. Accordingly the emperor wrote to the Pope, as did also Stylian of Neocaesarea and his friends.
Evidently, Leo and various anti-Photians considered that the Roman anathemas against Photius had never been lifted, so that even those ordained by Photius should be kept out of communion.
And the excuse at Florence and its validity though all signed but one, that the East was absent of a Patriarch which is why the Council isn’t recognized. Yet when Rome claims the exact same in regards to Constance, then we also see and here what happens. Its forced on us as fact.