For sure, one very noticeable bug is when the switches/splits are set to random or toggle, the train and the carriages get split on the tracks in both sides temporarily.
Some suggestions would be that the carrying compacity of a type of cargo increases the amount of 'cars' or carriages of that type. Also would be an interesting dynamic to split the one train up into a train for each resource. which would then bring about needed tracks for trains to get around each other and other scenarios for resource sinks.
And one more on the way the game is laid out. perhaps to make the sell points and stations fixed locations to make the player build out more from the minimal area needed to acquire everything needed to advance.
Those are just some things that I think will help get the game more involved for the player to managed and plan out. I have tons of other ideas but these are more foundation based.