Route Left Turn Issue

I'm building a route and I've got to the point where I need to make a left turn in the route. I am using the May 1st Nightly Build

Unfortunately, when I enter the .Curve command in with the radius specified, the route remains straight 


However, when the I input a right turn command it works normally

(will add proper curve rail objects when it finally works)

If I do a curve radius of less than 300m then the track will not turn either way
And if I place the left turn command in the previous block then it works as normal

I've attached it here https://drive.google.com/file/d/1OJrq4Rb7pBt8uv4bH7qzJE1JRQ5eK0RT/view?usp=sharing

This is a slightly complicated issue, and it involves turnbacks, although the left-hand only is a glitch (forgot to abs the radius value first).

Short answer:
Add something a bit further up and it'll magically start working

Long answer:
The OpenBVE engine isn't really setup to handle a full 180 degree turn, where the track / viewing angle intersects.

An AI train is disposed of 600m *after* the last object etc. is placed.
Thus, if the curve radius in the last block is < ~300, then the AI train will re-appear travelling towards the player train. (The train carries on following the last path in the world)