After pressing the "Import From" button, it is possible to leave the Structures tab by clicking another tab. However, the "Cancel" button only exists on the Structures and Overview tabs in the bottom bar.
If a player presses "Import From" and switches tabs, other gameplay actions can't be performed, but there is no interface element onscreen to cancel the trade route establishment action (it can still be done by switching tabs to one that includes cancel as an option, but this is not intuitive).
The "Cancel" button should be present in all tabs while "Import From" action is active, or switching tabs should cancel the import action.
Fixed so the Cancel button always shows up.