This was initially reported by someone else as a game bug here:
https://coigame.com/Topic/21269?page=1
Since posting my findings there, i've made some additional discoveries.
Issue:
When modifying the item throughput of unit station modules, trains stop at stations and fail to load or unload items at them. The train will not leave the station as a result. Recovering the train works, but it simply gets stuck again during the next stop.
Using the Mori++ Suite to change the station module throughput to the vanilla default (600/60s) fixes the issue.
Additional findings:\
- Seems to only happen regularly as of 0.8.8c, at least for me.\
- I have also modified the station capacity using this mod, but this seems to cause no issues. Its only the throughput setting that causes the bug to occur when set to anything other than vanilla.\
- Only affects unit station modules (electrified ones in my case), loose and fluid work fine.\
- The station module will say load/unload in the UI, but not actually do so and also not play the corresponding animation. Not sure if the animation plays a part here, but the other station module types still animate the loading/unloading process for loose and fluid cargo even at higher throughput speeds.\
- Occurs even on mixed trains, so long as the station and train have at least one compatible unit container that would normally get loaded or unloaded at said station
Mods in use:
Keybind Framework v2.0.8
Storage++ v.1.3.8
Retaining Walls Never Die v1.0.1
Train capacity adjustment v2.0.5 (i also tried disabling this mod, but the problem persisted without it)