The Mandela effect is an observed phenomenon in which a large segment of the population misremembers a significant event or shares a memory of an event that did not actually occur.
And there you have the New Testament!
It wasn't even a very large segment of the population, of a tiny little society, in a remote and primitive part of the Roman Empire.
Nobody who left any records of import noticed Jesus. Nor did they notice big portentous events like the eclipse and earthquake on Passover Eve.
Thousands of people knew Jesus, watched Him die, saw Him arise the next week, listened to Him preach again,
But then did nothing that anybody noticed. There is no records of Jesus influencing anybody enough to get noticed by the "authorities". If it hadn't been for St Paul(who never even met Jesus), I don't think that Christianity would have existed beyond the Diaspora. And if a Roman warlord centuries later hadn't found Christianity conveniently weaponizable, I doubt that it would have survived the 6th century.
the population misremembers a significant event or shares a memory of an event that did not actually occur.
That's exactly what I think happened.
Give me a reason to think Trinitarianism is a better explanation.
Tom