Rather to ask: If Pope Pius XII was a Holy Pope why did he bring Msgr. Bugnini into Rome for Liturgical butchery and why did he approve of the Masonic apostolate of the jew. Josemaria Escriva?

Sadly, one can go on for hours about the disaster that was the Pius XII pontificate.  While not a heretic, and therefore a legitimate pope, his was THE watershed papacy leading right into Vatican II.

During his protracted reign he ...

1) appointed the vast majority of bishops who would just a few years after his death bring us Vatican II (THE singlemost important job of a pope, where if he does this well, he need do very little more -- don't tell me that in each diocese you couldn't find a staunchly Traditional priest to make bishop of the diocese)
2) started Bugnini on his Liturgical experimentations and approved of garbage like the "Mass of the Future"
3) approved some of the earliest Ecuмenical conferences
4) opened the door to Evolution (didn't approve it, but allowed it to be discussed --- and we should know what happens when you give them an inch)
5) opened the door to the wide use of NFP (due to a failure at the very least to lay down explicitly what the conditions are for its use)
6) failed to consecrate Russia to the Immaculate Heart of Mary
7) failed to reveal the Third Secret of Fatima
8) failed to take any action knowing full well what was in the Third Secret
9) failed to condemn many of the heretical Modernists who were floating around and approved of before Vatican II ... there were thousands of these who went uncondmned and who came out of the woodwork like roaches after someone turns off the lights
10) failed to condemn Cushing for open heresy (along with many others all over the world who believed the same thing)

... and so on and so forth

oh, but he did punish Montini for ratting out bishops and priests behind the Iron Curtain ... resulting in their imprisonment and even deaths ... by not giving him the "red hat".

lose authority, like Pope Pius XI.

.

My opinion, Pope Pius XII went wrong in his pontificate.  Enough to lose authority, like Pope Pius XI.  IMO

So, you might as well deny the Assumption of Our Lady (Pope Pius XII) and "un-canonize" the Little Flower (Pope Pius XI).

The identity of a Pope is a dogmatic fact, lady, and you just denied two of them. The same goes for Pope John XXIII, who many sedevacantists decided to consider illegitimate despite the impossibility of proving that he had a habitual intention contrary to the common good of the Church or that he pertinaciously believed something contrary to the faith.

Ladislaus, you can't complain after you posted your list of little scandals of Pope Pius XII. I suggest that you read St. Matthew 18, 6-7.

That's what this forum is: an endless cornucopia of scandal, distraction, fables, outright heresy, pettiness, et c.

Our Lady told sister Lucia, Pope Pius XI did not consecrate Russia.  He will be like King Louis XIV, dethroned and beheaded.  1931.  Pope Pius !X, Leo, and Cardinal Manning, when defining Vatican I, knew nomination and election of Pope infallible, but can a Pope go wrong in his pontificate, yes.

Leaving aside the status of the popes after Venerable Pius XII, having nearly 3 quarters of a century in the Church I am unaware of Her stating anywhere that a legitimate sitting pope, the Vicar of Christ on Earth, can "lose authority".  Nor can I imagine Almighty God allowing this.  Certainly there have been Supreme Pontiffs who were less than ideal, and were undoubtable delt with at their particular judgement, but while alive as the Pope they held the authority of their office.  On the other hand, Martin Luther, John Calvin, Thomas Cranmer, and the like, taught that in their day the Popes and the Church had errored and departed from the teachings of the Apostles, the Church Fathers, and the plain words of scripture.  I am not going down that path, and I'm surprised to see such protestant views on a Catholic forum.

Again, speaking from the pre VII perspective, it is not the role of a lay person to assume the teaching authority of the Church by declaring (even if only as an opinion) who has been a legitimate Pontiff and who hasn't, who has authority in the Church and who doesn't, who has been legitimately lifted to the honors of the altar by canonization, and who hasn't.  If a Pope has lost their "authority" they certainly wouldn't have the authority to declare a Saint.

If Fatima is going to be appealed to, note that it is a private revelation approved by the Church.  While of great benefit, it's messages are not binding on the faithful as doctrine.