Currently if a connected column is added to the card in Kanban view, that information is only visible in the web or desktop apps. If you view the same Kanban card in the mobile app, the connected column appears blank. To see the information in that connected column, you must expand each item individually, instead of being able to see the information at a glance from the card, which is the whole point of putting data on the card in the first place.
The mobile app needs to be updated to make connected column information visible on Kanban cards.