Good that you took on simpler perspective and that you worked it into forest type things that you're doing well for a couple reasons. It's nice to look at, and there's only one notable problem with the perspective, which means you don't have to get 100 other things also correct. This is a very digestible fix.
The cross ties of the track are not conforming to a unified vanishing point that works with the base of the train. What makes it feel a bit off to me is that it's possible that the photo you were working from (assuming you were because of the problem) was likely shot with a wide angle camera lens thus creating an unnatural distortion that probably works in the photo because we tend to not question it, but it shows up in a painting where not every detail follows that distorted sensibility.
I don't know if I'm right about why it looks that way, but to my eye, it looks like the railroad ties are indicating that the tracks are leaning at an upward angle that the train is not aligning with. There's a slightly complicated way to plot such things, but if I were doing it freehand to work to my eye, I would stretch the vanishing point way farther away to the right and adjust the angle of the ties to where it generally should go. (an easy way might be to copy the tracks as they are and just distort the angle to see how it looks to you now that you've had some time away from the painting to see it more clearly.
If you do it on a new layer just to see if you can get the angle better, it would make a nice experiment for you and not damage this painting. But if you like what you do you can simply keep the new layer covering the old tracks.
Oh, just an addendum: I could be wrong, you know. So you have to decide how it sits with your eye.
Hope that makes sense. But this painting has only the one issue. Everything else is looking quite painterly and nice.
Great effort and you're like that determined locomotive driving along that track, so to pass through this forest you can make the tracks perfect without too much difficulty. Stay well, doctor!
Good one.
"Not a bit is wasted and the best is yet to come. . ." -- remembered from a dream