Building rail segment creates terrain, destroying adjacent rail

I have two adjacent train tracks, sharing a mining designation tile, with different slope profiles. In planning mode, they're both happy. (image 1)

The near track extends straight for an additional tile after the terrain begins to slope down, and for some reason it's decided that the first half-tile of that will not be elevated (even though the ground is dropping away). When I unity-build the track, it creates terrain to allow this, deforming the surrounding terrain as well. The far track, which needed the clearance of the terrain's previous grade, is not happy about this at all, and collapses. (image 2)
If I remove the near track again, you can clearly see the terrain deformation (image 3)

Adding a pillar in that space does not prevent the terrain deformation.

Save file attached.

I've had this multiple times myself. Easy way to reproduce is make a shallow trench a designation deep with ramps on the side and run the track over it.

this seems to be an intentional way to bridge rail to bridge, by using a tile on flat terrain immediately followed by bridge above terrain, workaround you can do however is make a little hump where the bridge jumps a tile up and then down to flat on flat terrain, ramps to flat terrain dont need a special terrain bump (excluding ramps going down a terrain ramp)

i feel like they should be able to just let the bridge tiles extend to the beru edge of the terrain, but maybe a problem is that the bridge would then intersect with the terrain ramp below it