Last night I clicked "mark as used" on one of my tickets in The Trainline app. It was for the first part of a set of advance single tickets, and I wanted to remove the first leg of the journey from the app, so I only had the next day's tickets in the app. I clicked through the warning to say "you can't undo this", not realising until immediately after I clicked it, that it meant the whole journey would be marked as used, not that single leg of the journey. Given this meant I now had no train ...
