John XXII taught that souls do not enter Heaven or Hell before the Last Judgement. He gave speeches, wrote letters and even a book about it. The clergy went into an uproar, particularly the faculty of the University of Paris. On his deathbed, the pope said he accepted whatever the Church would define about it. His successor clarified the question.
Regarding Pope John XXII
"However,
he taught this as a private teacher, not as Pontiff, and he held it theoretically or for the sake of debate, thinking that he could be deceived in these matters and permitting others to think differently until the question should be decided authoritatively. Hence he took care to have the matter studied by the Doctors, and frequently summoning debates in his presence on this point, he was prepared to abandon his opinion if it was shown to be against the faith. Indeed, on the day before his death he ordered a declaration of the true doctrine in the presence of all the Cardinals, etc. He said that previously he thought differently about this matter by pondering it and speaking about it.
In this way he prepared the way for his successor, Benedict XII, to proclaim a definition of the true teaching [see Denz. 530-531]."
- Fr. Joseph F. Sagüés, S.J., Sacrae Theologiae Summa IVB: On the Last Things, trans. by Fr. Kenneth Baker, S.J.
Prior to Pope Benedict XII's definition, the issue was up for discussion. Pope John XXII never formally taught any heresy to the Church...that's just a bunch of malarkey.
It's also a well know fact that Saint Bernard also held to the same opinion as Pope John XXII
"St. Bernard [Doctor of the Church, 1090-1153] often taught that deceased just persons immediately after death will obtain immense happiness, but not the beatific vision until the resurrection [of their bodies]."
- Fr. Joseph F. Sagüés, S.J., Sacrae Theologiae Summa IVB: On the Last Things, trans. by Fr. Kenneth Baker, S.J.