Even if you change things in the app, the ownership of the ticket is with the travel agent who has to reissue the ticket if it is a volontary change. The TA behind the CapitalOne dropped the ball and probably didn't reissue/sticker the ticket correctly. They would have been informed of the rebooking and subsequent no-show on the 16th and 26th. I would confront CapitalOne why they didn't perform their duties as your travel agent.