Ai Trains Slowing To A Crawl

Can anyone help me solve the problem of some AI trains suddenly slowing to a crawl or stopping completely, thus mucking up the scenario?

 

Just wondering...
Have you used any 'Stop at Destinations Instructions', the hand icon, in the AI's task list with a speed of zero,
in which case the train will stop.
Unlike the player train, AI seems to try to achieve given speed at the instruction point.
If it has been told 1 mph then it will slow to 1 mph, so try entering the speed you want it to be going at.

 

If it's not that then the trains are "creeping" and basically means the AI has got confused - perhaps the player has done something the dispatcher didn't expect, even if it was the author's intentions?

 

I heard about this on an ATS twitch stream. It happens when one of the AI trains loses it's path.

 

Is this on an official or third party scenario? (AP, ATS, JT, etc. are technically third party unless sold on Steam. but even then DTG has no control so it can be deemed third party.)

 

I get this issue with trains going over junctions sometimes where it's moving fine until it goes over a junction then it's going at like 1mph