I made this presentation because it's SUCH AN OBVIOUS problem with flat earth, but the southern hemisphere is such a big nail in flat earth's hands, feet, and a giant dagger in their chest, that I only picked this one because I have fond memories of arguing with a flat earther over southern stars. On youtube, I was commenting under Dave McKeegan's (a photography channel who debunks flat earth) videos to see if anyone would respond. Someone did, and they asked me to pull up a Gleason map. I did, noticed this problem immediately, and kept asking them why someone in south America and someone in Africa could look AWAY from the center and see the SAME southern cross. OBVIOUSLY, he just kept saying "Because that's where it is! Pull up the Gleason map and all will be revealed" or something like that. The problem is that you can't truly explain geometric problems with flat earth (like this) with only text.
You can link to this resource online if you ever have an argument with a flat earther online and it drifts towards something something SOUTHERN HEMISPHERE CONSTELLATIONS!!! The False Report Detector is from https://scratch.mit.edu/projects/1284923512/