Chapter 2: Flamsterd

After stepping off Pinmel waits for the others to cross and then heads down

Having watched what Pin did gracefully hops in the same pattern.
"Good Job figuring it out. " Atlas pats Pin on the back.

As Atlas hops on the first tile (1) the same voice repeat "You have failed the challenge! Proceed to escape route immediately! Hurry!",

The piece transformed to stairs magically changes back to floor, doors start opening...

You avoid taking any damage, but the hole in the floor closed.

Well, I believe the place is designed for a single apprentice undertaking the test. Atlas stepping the tile Pin stepped already triggered the fail, I believe. He suggests Pin to reset the room buy touching the the ball.
After repeating the sequence the rest of you simply go around and enter through the hole Pin made earlier and are able to go down the stairs.

Together with the rest of the team that was guarding the entrance