The Mufti, Shaykh Abdul Azeez Aal Ash-Shaykh, may Allaah grant him good health, was asked the following question:
ماحكم الخروج من المسجد بعد الأذان بصفةٍ مستمرة ؟
What is the ruling on constantly leaving the masjid after the adhaan?
إن كان الخروج لمصلحة بأن كان يذهب لمسجدٍ يؤم به أو أنه يذهب لقضاء حاجته وقد لا يعود فهذا جائز ، أما إذا أذن المؤذن ولم يكن له عذرٌ شرعي فخرج من المسجد بعدما أذن فقد رأى أبوهريرة رضي الله عنه رجلاً يفعل ذلك فقال : أما هذا فقد عصى أبا القاسم صلى الله عليه وسلم .
If his leaving is for a benefit, such as if he were to go lead the prayer at a different mosque or were to go fulfill his personal needs though he may not return, then this is permissible. As for if the mu’adhin performs the adhaan while the individual has no legitimate reason, and [then he] were to depart from the masjid after the adhaan was made, then indeed Abu Hurayrah had seen a man doing that, so he said: “As for him, then he has verily disobeyed Abaal Qaasim [i.e. Prophet Muhammad] sallahu alayhi wa salam”.
Ash-Shaykh Muhammad bin Saalih al-Uthaymeen, rahimahullah, said:
والذي نرى أنه إذا خرج ليصلي في مسجد آخر يعلم أنه يدركه فلا حرج عليه ، لكن لا ينبغي أن يفعل لئلا يقتدي به من يخرج ولا يصلي
…What we hold is that if he were to leave to pray in another masjid where he knows that he can catch [the congregation there], then there is no harm upon him. However, it isn’t appropriate for him to do t hat since others may follow him [in that] of those who may just leave and not pray. [Listen / Download]
Also, here is a similar fatwa by Shaykh Saalih al-Fawzaan.
AbdulFattaah Bin Uthman