Below is a link to a save file on DropBox that will demonstrate winning on the first turn.
https://www.dropbox.com/t/DakRJmSQiGS33D2yHere is a screen snapshot of the setup for the game. I am playing as a custom civ against the Yor. I have started more than 1 game with this setup and every one ends in victory on the first turn.
There is a bug in the map generation of tiny maps that makes it not set the AI on far distance, it is known and being worked on.
I'm not sure if same bug but I have gotten Gigantic Far with a civ or too missing.
As well it has been reported that Gigantic Far and 23 AI can cause each sector to have an AI but the players sector gets the left-over AI.
Again, it is known and is being worked on.
It is not an easy fix.