Is it permissible to repeat the Fajr prayer at home due to doubt about its having been established in the mosque before its prescribed time?

The Fajr prayer has two adhans (calls to prayer): the first is before the time to awaken people, and the second is at the beginning of its time.

If a worshipper doubts that the prayer time has begun, or if they predominantly believe it has not, then it is impermissible for them to start the prayer. If they do so, their prayer is invalid and must be repeated, due to the lack of certainty in fulfilling the obligation.

One may follow the imam of the mosque or the muezzin if they are trustworthy and knowledgeable about prayer times. However, repeating the prayer at home after performing it in the mosque without a legitimate শরعي reason is disliked (makrooh).