Observations on the 2 latest videos (with the engine warmed, and idling):I say it was BOILING!
And I don't think anyone can convince me otherwise.
Video 1- the fuel filter is only 1/3 full while running. Same as the first 2 videos you posted. As you pour water on it, it starts to gradually fill more.
Video 2- the fuel filter is nearly full to capacity as you are pouring water on it.
What changed between these 2 videos?