@razatd
For example, a common misconception that Flat Earthers have is that “water seeks its own level”. They have never made an effort to learn anything beyond a few YouTube videos.
There is no "they". Flat earth researchers are most often independent and they tend to differ substantially in both approach and conclusion as a result. It sounds like you have some experience with youtubers - but none with earnest flat earth researchers.
Water's surface does indeed seek its level at rest and this is a demonstrable natural law of hydrostatics that has stood unchallenged for centuries. In order to refute the law, you MUST repeatedly/rigorously measure water doing something other than that (at rest, under natural conditions, and barring irrelevant miniscus effects - which are also laws and don't in any way contradict the one we are evaluating). No one can or has, which is the reason the law still stands today.
Flat Earthers have still not been able to create a map of the World which shows how disinterested they are in gaining any real knowledge.
Yes, I've often heard it said that cartogrophers are the true height of intellect and knowledge. "Give me a good map, and I won't need books or scientific study" - they say.
Essentially, no one is engaged with cartography (most especially not to determine the shape of the world - which is BELIEVED to be already known), and this is something you should understand.
when Flat Earthers are cornered they just leave the thread. They don’t want to be proven wrong because they don’t want to improve their knowledge.
Yes, I'm sure that is the main reason that people end conversations with you - fear of improving their knowledge.
Many times people choose not to repeat themselves when they have said all that is relevant, other times - life gets in the way (sometimes I respond long after the fact when I get a chance).
This might come as a shock, but the last person who speaks does not "win" the conversation (you can't win a conversation, but you can lose it). In many cases, they have simply ended it.
Instead of improving their knowledge they chose to remain ignorant.
Old habits die hard!
Take yourself for instance. You think (because you were taught, and are now repeating) the southern cross proves something about the shape of the world.
You have likely already been explained to - that looking up to study the shape of what is in the polar opposite direction of you is both unscientific and powerful stupid. But your habit persists, because you "learned" by conditioning through rote under the guise of education - and fixing what has been damaged by that process will take the same repetition that was required to ingrain it in you (in this case, against logic and reason)
Why is there such a lack of scientific interest in this community?
You aren't talking about science, you are talking about cartography... It ALSO isn't useful to determine the shape of the world, as that is in no way its purpose. To try to misuse it in that way presumes measurements that have not been collected.
Why are Flat Earthers not joining effort to map out the surface of the Earth?
Because mapping is NOT the same as measuring! There are many flat earth researchers engaged in measuring the (local, typically) earth's shape and they have collected some very interesting findings!
One day, the maps will become a priority to fix / reconcile with reality. However, we don't fix things unless they are broken. If the map is useful (or we believe it is), then we keep using it. The shape of the world doesn't enter into it. It's about bearing and duration - the distances can be completely incorrect (especially with local motion, for example - currents / jet-streams) and still be useful / "correct" enough for our purposes.
You can disprove the Globe Earth map.
There are many flaws to harp on about existing maps and always has/will be - why bother? It doesn't have relevance to the shape of the earth. If you want to know the shape of the world with certainty - you have to measure it rigorously (maps aren't for measuring the world, nor do you measure the whole world to make them)