Two Congregational Prayers at the Same Time
What is the ruling of holding two congregational prayers at the time?
Holding more than one congregational prayer (salat al-jama`ah) at the same time or mosque would divide the community and cause confusion among the Muslims. In addition, it would leave the choice to the people to come at whatever time they wish.
There is no doubt that holding a second congregational prayer in the mosque aside from the main one is prohibited. If the second group prayer is not intended to cause dissension and the congregants were unaware of the first group, the second congregation is valid and does not entail any sin.
To know the answers and more about the rulings of holding two congregational prayers at the time, you can watch this short video with Dr. Muhammad Salah.
Source: Huda Youtube Channel.