Frankly, I so don't care about this particular topic. Like at all. For me the evidence for round Earth is sufficient. I trust my eyes, together with examples you discard, as well as testimonies of other people which all align with round globe more than if the Earth was flat. For you that's clearly not the case. But as I said, I'm not here to convince you of anything. So, your next best bet is to fly really really high or walk the Earth on a line where the Sun will be always overhead (or at the same elevation) -- you will either fall off Earth or end up in the same location where you started. That should settle it.