There are several things that this model of flat earth does not address and that anyone that has had the opportunity of living at different latitudes has experienced. One of them is the path the sun follows at sunrise, noon and sunset on a given day. For people who live along the equator (e.g., in Quito) the sun follows a vertical path, up from sunrise to noon and down to sunset, and they always get 12 hrs. of daylight (+/- few minutes) every day of the year regardless of the season. North of the equator, during spring and summer, if you stand outside your house facing exactly to the East, the sun appears to rise from your left side, at noon it will be slightly on your right side and back to your left at sunset (not a vertical but inclined path). The farther north you go, the sun rises more to your left and experience longer daylight time (e.g., Houston vs Anchorage). However, regions north of the Tropic of Cancer never experience the sun at their zenith (vertically on top of your head). In cities north of Anchorage, like Fairbanks, on June 21st the sun follows a path that circles the horizon.
At the Equinoxes, anyone in the world experiences the sun rising exactly at the East and setting at the West, but only cities along the Equator experience the sun at their zenith. Autumm and winter, again, north of the Equator, the sun always rises on your right side if you face exactly to the East. The northern you go, the more to the right side.
If you have never experienced this, it will take some time to digest. This phenomenon can only be explained if the surface of the earth is curved at least from a North-Southwise direction. The sketches I attached can give you a better idea. You can compare observations between cities in the US like Seattle, Chicago or New York vs LA, Houston or Miami if you have family or friends. Very few people in past centuries had the chance to travel as much as we can these days and experience these phenomeonos themselves.