Is it obligatory to repeat the ‘Isha’ prayer after doubting between the third and fourth rak‘ahs, then favoring the fourth, then the doubt returning, then settling on it being the fourth, and performing the prostration of forgetfulness (sujud al-sahw)?

Scholars have differed on the ruling concerning a worshipper acting on their predominant assumption during prayer. Some of them have stated that such action suffices. And what is done based on predominant assumption is considered correct by some scholars, and the prayer is valid and does not need to be repeated. And doubt after prayer is not to be heeded.