The question may seem a little strange to you, but the legendary part of the game also matters.
There is some inconsistency.
Records of the Vaults of the Elders say that they eventually made a duplicate of the Tower artifact and restarted it, but began to suffer from the Maelstorm and its creatures, and took refuge in their Vaults.
And Siptah’s diary tells us that at the time of the landing of the Stygians, the Tower was no longer working. The last records of the diary says that he prepared everything, made a copy of the artifact and enters the Tower to start its work.
It is unclear why the Tower did not work before the arrival of the Stygians. What am I missing? I would be grateful for your answers.