Does a person need to re-perform Isha solah four rakaat when he reached home,
although he has done the Isha solah two rakaat jama’ with maghrib whilst he was
still in musafir?

Praise be to Allah;

A traveler may combine the Maghrib and ‘Ishaa’ Prayers, shortening the ‘Ishaa’ Prayer to two
raka’aat only. Once one has done so, one is resolved of obligation and need not re-pray the
‘Ishaa’ Prayer even if one reaches home during the time of the ‘Ishaa’ Prayer.

Allah the most Exalted and Knowledgeable knows best.