Pope John the 22nd. (not the 23rd) preached from the pulpit that no one who had already died was in the presence of God. But that they would only see God after the final judgment.
He was questioned, rebuked and resisted in this error by his own subordinates until finally on his deathbed he recanted.
His preaching and ideas were not an act of the Magisterium.
So you're saying the pope is NOT infallible in matters of morals and faith? You're saying he taught heresy?
Or is there more to this story?
If it's the former, then the Church is built on sand, not on Peter. If it's the latter, then it doesn't apply here.