Hope you’re in the best of health and imaan inshaAllah.
I thought that nikah can be done in a masjid and it is according to the Sunnah as well. One of the imam said that it is not Sunnah to do the nikah in a masjid. Is that correct? If so then where should be the nikah done according to the Sunnah? May Allah reward you with goodness.
Nikah ceremony can be done in a masjid if you wish. But we do not consider this as a Sunnah or an act of worship. We can do this because it could be convenient instead of doing it at our houses. Nothing is wrong with this. The Saudi permanent committee of Fatwa allowed it.