This is so frustrating. Just tried 3 missions in a row in the same omnia fissure, and had to keep restarting because the rounds kept ending before enough reactants spawned. Often times, when there is enough reactant spawning, there is one person 2 rooms away while we're trying to keep the exolizers closed. Sometimes, the players defending are punished because a random squad member is in another room where reactant spawns, and we're unable to leave the exolizer room or the mission will fail -- thus forfeiting the reactant and being unable to open relics.