Version information:

• Platform: Windows 10
• Version: 24.10
• Build/commit: 52acc01

Describe the bug

1. When trying to place a Narrow Gauge Steep Slope Curve:
   1. The preview of the track piece won't disappear until you save & load, and turns your mouse into a ghost-track paintbrush.
   2. If you try to place it, it will fail with the "Raise or lower land first" message, even if the terrain is suitable. Narrow Gauge Steep Slope Curves cannot be free-placed on flat land. #2692
2. When trying to remove a Narrow Gauge Steep Slope Curve, it will fail with the message "Can't build Narrow Gauge Track..."

To Reproduce

1. Load a game with narrow gauge rails available, such as "Swiss Alps 1930"
2. Open the narrow gauge track building tool
3. Select "Steep Slope Up" or Down (the 45º ones, not the 22.5º ones) and Left- or "Right-Hand Curve (Small Radius)"
4. Move your mouse cursor across the terrain, and attempt to place it somewhere by clicking on a suitable piece of land.
5. Build a different narrow gauge track piece, or right-click on an existing one, and then build the steep slope curve from it.
6. Attempt to remove it by clicking the bulldozer icon, or by using the 'Remove at current position' keyboard shortcut.

Expected behaviour
construction

Screenshots
Screenshots show me attempting to remove a Curved Steep Slope track after building one, after leaving behind a bunch of white previews of ones I didn't end up building.

Additional context

• Issue does not happen in original Locomotion.
• I'm not sure if this issue is specific to Narrow Gauge or not, as I cannot find any other type of track or road that has Steep Slope Curves available.