They did not spend the night in Mina because the camps were located outside it due to severe overcrowding, as they were told.

Question:
May Allah reward you with good and do you well. A listener who referred to his name by the letters F, N, H, and B sent a question, saying: In one of the years, my wife and I performed Hajj as part of one of the groups. When we arrived in Makkah, we were surprised to find that the camp was outside Mina due to severe overcrowding. We spent the days of Tashriq in our camp with the group, outside Mina, as close to Muzdalifah as possible, according to the signboards in the sacred sites. My question to you, Honorable Shaykh: Do we bear any sin or blame? Is our Hajj valid? Please note that when we registered with the group for Hajj, they told us the camp would be in Mina, but when we arrived, this was the surprise. Please note that many camps are located outside Mina, just like ours. Please give us a ruling, and may Allah reward you. May Allah reward you with good.

Answer:
It is obligatory for the organizers of the pilgrimage groups to fulfill the conditions agreed upon between them and the pilgrims and those performing 'Umrah, because Muslims are bound by their conditions, as the Prophet (peace and blessings be upon him) said, "Muslims are bound by their conditions." And Allah (Exalted and Majestic is He) says: Therefore, it is not permissible for the organizers to be lax in this matter or to neglect the conditions they have contracted with the pilgrims and those performing 'Umrah. Likewise, and even more so, it is not permissible for them to do things that interfere with the rites of the pilgrimage, such as standing at 'Arafah, staying overnight at Muzdalifah, descending to Mina, and staying there during the days of stoning the pillars. These are rites, and it is obligatory for the organizers to enable the people with them, those who have contracted with them, to perform their rites. However, if they are forced to stay outside Mina because they did not find a place, despite making an effort and checking, they should stay with the pilgrims near Mina. Allah the Exalted says: So if they make an effort and strive to find places in Mina but are unable to, they should stay near it with the pilgrims, at Muzdalifah or in any place adjacent to Mina. Allah the Exalted says: And as the Prophet (peace and blessings be upon him) said, "When I command you to do something, do as much of it as you are able." Then, as for the pilgrims who have the ability, they should come to Mina at night, come to Mina at night, and remain there for most of the night, then return to their tents. But if they are unable to do this, unable to come to Mina because of its distance, or because of hardship they cannot bear, or because there are women among them who cannot go, or the sick, there is no harm in their staying in their tents. In this case, they are excused, and the obligation of staying overnight is lifted from them, not because of an excuse that they could not have avoided. Yes.