To answer your question OP, on a ball earth rotating around a sun that is rotating around a fixed point within the galaxy, sun dials should only work once or twice a year, and they shouldn't be perfectly circular because the earth is supposed to be revolving around the sun on an elliptical path
Also, high noon on Jan 1 should actually be exactly high midnight on July 1, exactly 6 months later on the other side of the sun. The block of sunlight that each area experiences should be moving back and forth between at 12 hour interval
Also, constellations should never been seen the same way from night to night, much less over millenia
Also the concept of gravity causing water to stick evenly to a sphere cannot and has not been recreated on earth in any experiments that I've seen
Also, you should be able to see the earth's curvature over large bodies of water, yet you can't
Also, who says a flat earth is supposed to have an edge?? That's just how pseudo-intellectuals dismiss something they don't understand
Also, many people acknowledge that very advanced civilizations lived in the past. Civilizations that mapped out the constellations perfectly and utilized advanced technology that didn't hurt. Most of that technology we don't understand to this day. Every single one of said civilizations were under the impression that the earth is flat. This is significant no matter what you believe
I can definitely keep going