PC Custom Rolling Stock Not Appearing On Clinchfield

I am finding, (Along with others I suspect), that custom liveried hauled rolling stock is not spawning into the game on Clinchfield. I have a few custom boxcars and reefers available but they are never spawning into the game in journey mode, Scenarios or Timetable mode. I also have some custom Clinchfield F7 & SD40 locos but these items DO spawn into the game randomly as they should in all modes.

Therefore this issue ONLY seems to affect freight cars and not locos on Clinchfield.

I am on PC but unsure if this is also an issue on console too?

 

It's an issue also on console

 

This isn't new, although it's possible that the bug on CRR is a different one from the old one: custom liveries never spawn on German routes, ever.