This is caused by a fisheye lens?
No, it’s caused by perspective.
You often cite railway tracks appearing to merge so you do understand that parallel lines appear to converge by perspective.
Your understanding of perspective is so weird, you think it can cause the sunset when it can’t and you then forget about it when looking at photos like this.
As Bad Puppy suggests, you can test this easily yourself with a piece of paper. Draw some parallel lines and note that from an angle they appear to converge.
I don’t see how this “problem”, if it was one, would be any more explicable with the FE sun.