Big Brother was controlling the releases of the boxes but the fact Gemma had immunity was completely luck by her choosing that podium

^ Pretty much.

if it was a fix, Jeremy or Stephanie would have gotten it.. Why would Gemma need immunity? she came top 2/3 twice now.

It would only happen to the ones producers don't want to lose and is possible to be evicted(Gemma isn't in danger to be evicted anytime soon) It's not a fix at all, it was all luck.