The Growth Anomaly of TON 618: How did primordial supermassive black holes grow beyond standard galactic mass correlations? [duplicate]

​We know that standard supermassive black holes scale with their host galaxies (for example, Sagittarius A* is about 4 million solar masses inside a 100,000-light-year galaxy). Even considering galaxy mergers or feeding rates (like active black holes in systems such as the Phoenix Cluster that consume massive amounts of solar masses per year), scaling up to 66 billion solar masses for TON 618 seems mathematically and physically inconsistent with the expected timescales and normal accretion limits (like the Eddington limit) in the early universe. ​If standard stellar consumption or normal galaxy mergers cannot account for this extreme mass disparity relative to its host environment, what are the leading theoretical mechanisms proposed to explain how such an ultramassive black hole grew so massive, so quickly?