Here's a video of three flat-Earthers discussing (arguing) about it with three round-Earthers: https://www.youtube.com/watch?v=Q7yvvq-9ytE. They appear genuine, and remind me quite a bit of the anti-evolutionists I sometimes argue with (and who are definitely genuine).

And then there's "Mad" Mike Hughes, who just managed to kill himself in a rocket he was hoping to fly high enough to see that the Earth wasn't curved... or something. https://www.bbc.com/news/world-us-canada-51602655