I think this last bit is interesting.
He has said he's had his eyes opened since about 15/16 years ago. Used to believe it was a globe but then slowly realised...
Coincidentally the rise of youtube was about 15/16 years ago.
I might be wrong in my assumption, but as I've said previously on here, though relevant again, I'd expect he went down a bit of a rabbit hole. Convenient explanations, suddenly makes more sense than something that requires a bit of education to understand (we've saw earlier his lack of understanding of how education/higher education/further education etc works).
The earth, solar system, galaxies, the universe, physics, chemistry, maths all vast and complex things. Daunting at times. Hard to understand for many people.
So when a video goes something like "THEY say we're on a spinning ball rotating at 1000 mph, yet we can't feel it?! Does that seem even remotely possible to you?"
The rube who is watching it suddenly goes "exactly! That's much easier to understand, THEY are full of bullshit".
And so it goes.
Now, after that bit of waffle, I'll get to my point. I think he's at a point after having every single argument absolutely ripped to shreds in here that he just can't admit there's any doubt, or that he was wrong. He thought he was wrong about the globe until he was brainwashed. But now has internal conflict because he knows he's wrong about the flat earth.
It's embarrassing to be scammed, you feel guilt, shame and foolish.
Admitting it now would be worse than just putting his fingers in his ears and shutting his eyes and going 'la la la earth is not a globe, you have no proof la la la'.
Every single thing has to be denied or obfuscated or deflected because his whole premise is the wobbliest of jenga towers. A line of dominoes ready to go. Can't even accept a distance between two places, or right angles are 90° because if that one thing is agreed to, several other things are also correct, and if those several others are correct then so are these dozen other things.
In summary, knows he's wrong, can't back down. The behaviour of a religious zealot.