The item level required for the Herald of the Titans achievement has been updated in Dragonflight Beta Build 46144.
To be eligible for the Herald of the Titans title, your group must defeat Algaon at level 30 without anyone wearing items higher than Item Level 107 (up from 35).
Herald of the Titans – Defeat Algalon the Observer at level 30 without anyone in the raid wearing items higher than Item Level 35 107.
Title Reward: <Name>, Herald of the Titans