I was trying to kill the final SoS boss for many hours today with various teams. The last team was quite competent, and we frequently took about half of the health off the boss in the first run. However, the longer we played, the more often it happened that we couldn't charge all orbs because no flames spawned, or we couldn't open the boss' shield because the 3rd orb wouldn't drop. Very often this happened during the second phase, after we had damaged the boss.
Is this caused by bugs or network inconsistencies, or did we fail to satisfy some requirements of the mechanics?