In MSTS AI trains run up to the end of their path, as defined in the MSTS AE. In OR (rel. 2322) AI trains run, at least in the cases tested, up to the end of the section that contains the end of their path. If the section is not within a station, the difference can be also many Km, leading to undesired results.
A demo activity for the USA1 route is attached. An AI train has a short path that terminates about 100 meters after the first signal. The player train is on the parallel track to observe the AI train.
In MSTS the AI train runs up to the end of its path and disappears.
In OR the AI train runs beyond the end of its path, up to the first switch it encounters, which is some Km farther than the end of the path.
First fix in release x.2425.