Q: Does reciting same Zamma Surah in both 1st and 2nd rakats void the Salah?

Answer: In case it is a Farz, Wajib, or Sunnat-e-Muakkadah Salah - If a person, on purpose, without any need, is reciting the same Zamma Surah in both the Raka'at of the Salah after reciting Surah Fatiha, then it is Makrooh-e-Tanzeehi. It is also Khilaf-e-Aula, meaning it is not the best practice. However, if a person does it by forgetting or the person just knows one Zamma Surah, then it is not categorized as Makrooh-e-Tanzeehi. The Namaz is still valid in both the aforementioned cases.

In the case it is not a Farz, Wajib, or Sunnat-e-Muakkadah Salah - Reciting the same Zamma Surah in both the Raka'at is not categorized as Makrooh-e-Tanzeehi. The Namaz is valid.