I totally agree. Yesterday i did a run of cascade omnia fissure, i spent 25 minutes with my squad, and i only managed to open 3 relics with them (1 of the 3 i couldn't crack alone because all the reactants disappeared after 1 minute), and the stalker was bugged and stayed invisible for about 10 minutes, which also wasted the steel essence for 10 minutes.
We also tried not killing every mops for them to spawn as corrupted and drop reactants, but in cascade it doesn't work because of the method that the mission goes through, 4 exolisers is 1 fissure run, and we can't stop killing or we lose the mission.
Please DE address this issue. Thanks in advance