Doing the [Breaching the Tomb] achievement, in the “Mark of the Sentinax” step, I noticed that the “Shadow of the Sentinax” buff is present when under the Sentinax itself, but no portals were to be found. Mobs and elites occasionally drop beacons, but they behave oddly. If you use a beacon you get to spawn not only 1 but 3 portals and these will spawn mobs just fine, but will despawn at the same time. Any mobs killed and loot will despawn together.
Shard Times was completed as a requirement.
Please advise.