It is recommended to pray maghrib at its earliest times and delaying it for too long could be disliked,

The Hadeeth:

عن العباس بن عبد المطلب قال قال رسول الله صلى الله عليه وسلم لا تزال أمتي على الفطرة ما لم يؤخروا المغرب حتى تشتبك النجوم

“My Ummah will not cease to be upon the fitrah as long as they don’t delay Maghrib until the intricate patterns of the stars become visible”

(Reported by Abu Dawud 444 and others. Authenticated by al-Imaam Albany)

Ash-Shaykh Bin Baaz, may Allah have mercy upon him, said:

الأفضل عدم التطويل ؛ بل يقيم بعد مدة يسيرة ، بعد الأذان بمدة يسيرة عشر دقائق ، ثمان دقائق

“…What is preferable is that (the time between the adhan and the iqamah) isn’t prolonged. Rather, he should do the iqamah shortly after; shortly after the adhan (for maghrib) by eight minutes or ten minutes”

، أو ما يشابه ذلك ، ولو أخذ نصف ساعة أو أكثر قبل غروب الشفق فلا حرج ، الصلاة صحيحة وكله وقت

“Or around that time period. And if he were to delay it for a half an hour or more before the disappearance of the red evening twilight, then it is okay (and) the prayer is valid; it is all from the time of maghrib”

، لكن الأفضل في المساجد ، والمسلمون في البيوت : المرضى ، والنساء الأفضل أن يصلوها كلهم في أول وقتها ؛ اقتداء بالنبي عليه الصلاة والسلام .

“However, what is preferable for the mosques and for the Muslims praying at home from the sick and the women is for all of them to pray at its earliest time, (This is) in order that they take the Prophet, alayhi salaatu was-salaam, as their example.”

(Reference)

Also Ash-Shaykh Muhammad bin Ibrahim Aali Shaykh rahimahullah, stated in his fataawa:

وأما المغرب فلا يؤخَّر أَكثر من عشر دقائق ، لما وَرد فيها من النصوص الدالة على تعجيلها

“…As for maghrib, then it shouldn’t be delayed for more than ten minutes (after the adhan) due to what has come of proofs indicating that it should be prayed at its earliest time…”

So, you should strive to pray at those mosques that pray maghrib early and if you don’t find except a mosque that prays a little bit later than usual then you can pray along with them in congregation. (This is) with the condition that they don’t delay it until it is feared that the time of Ishaa will come in. And Allah knows best.

~ Abu Fajr AbdulFattaah bin Uthman