Train Stops appear to be reading the trains contents when connected to a circuit network even when the "read train contents" checkbox is unchecked. This can be fixed when the train is at the station by checking, then un-checking, the "read train contents" checkbox, but if the train leaves and returns it reads the contents again if the checkbox is unchecked. Moreover the train stop only reads the contents once, and does not update to show the correct amounts of items in the train as they change, when the checkbox is unchecked. If the "read train contents" checkbox IS checked then the contents show, and update as they change, as expected.
Screenshots follow:
Contents of train wagon
Contents shown in circuit network
Current Train Stop Settings
Circuit Network after checking, then unchecking, Read Train Contents