"The Great Vault"

Can you please explain to me how the main story line quest “The Great Vault” is a level 29 mission when the mission prior to that “Angels and Speed Demons” was a level 30 mission . This screws up the loot drops since I started Angels and Speed Demons at level 30 and I’m now level 29 doing the main mission that just spontaneously reversed levels. Any explanation would be appreciated.

Hmm strange. But really doesn’t matter once main game is finished and you unlock true vault hunter. I’m currently up to carnivora and every mission both main and side are now level 50