Ruling on the latecomers performing the 'Isha' prayer during the tarawih

Question:
He says: It often happens in Ramadan that another group enters and prays 'Isha' in congregation, while we are praying tarawih at that time. Is it obligatory for them to join us in the tarawih, or should they pray individually? May Allah reward you with good.
Answer:
If they pray individually, there is nothing wrong with it, and it is perhaps more preferable, in order to avoid the disagreement. And if they pray tarawih with you, and when the imam concludes the prayer they stand up and complete it, there is nothing wrong with it according to the correct opinion. But if they pray alone, that is the most correct view according to everyone. And if they pray behind someone who is performing voluntary prayer, then they stand up and complete it, it is sufficient according to the correct opinion, and it is valid. Yes.

The presenter : May Allah reward you with good, and may He do you good.