When the Imaam and/or Follower are Travellers

Q: Salaah-112: Will the salaah of a Musaafir be valid if he followed a Muqeem (non-Musaafir) and performed Qasr salaah?

Answer: When a Musaafir follows a Muqeem in salaah, he will have to perform the full four Rakaahs salaah. His salaah will not be valid if he does not do this.

Fatawa Rahimiyyah vol.2