See at screenshot.
LMR "Planet" 2-2-0 and 3t Bulk Wagons
This bug presents with other combinations too.
Simutrans Experimental 11.12, Pak128.Britain Experimental 0.9.0
Thank you for the report. This is a longstanding issue which is somewhat difficult to fix, although I have tried in the past to do so. It is a code bug rather than a pakset bug. It occurs only when the train reverses, and as a result of a differing alignment of vehicles when oriented in a different direction.
If any of the Standard programmers who is familiar with the relevant parts of the code can suggest why this might be happening I should be grateful for any insight.