Turntables and slopes refusing to render track fill, either partially or fully.

[Bellpiper]

Describe the bug
When spawning or creating a turntable, the preview shows the turntable has its textures filled beneath the rail. Actually spawning the rail only produces textures on the edge 'ring' of the turntable, and oddly enough the underside. Replacing the block does nothing, and this occurs both in singleplayer and multiplayer.

How to reproduce
Steps to reproduce the unwanted behavior:

Build or spawn turntable of any size
Profit.
Expected behavior
Turntable spawns in with fill beneath rails.

Screenshots
https://pasteboard.co/JOR7Shr.png
https://pasteboard.co/JOR88FW.png
https://pasteboard.co/JORcf9j.png (Preview shows no issue)
https://pasteboard.co/JORcpyA.png (Actual has missing textures. Turntable behaves similarly)

System Information
OS: win10

System Memory: 16gb

Allocated Memory: 2gb

CPU: "Intel I7 4790k"]

GPU: MSI GTX 1070

IR-Version: 1.16.4

Forge-Version: 1.16.4/1.16.5

Modlist
Create, TrackAPI, Immersive Railroading, Immersive Engineering, Universal Modcore, JEI

Additional context
Not sure if this is a trackAPI bug or Immersive railroading.