I say, and with God's success: The Tarawih prayer is different from making up the Isha prayer, so one must intend one of them for it to be valid. However, if you intend to make up the prayer and you are against the Imam of Tarawih, it is not permissible; because it is not allowed for someone with a mandatory prayer to follow someone who is performing a voluntary prayer, as the mandatory prayer is stronger, so your prayer behind him is not valid. And God knows best.