The Sustaining Gift Details page will only show the "final" decline that occurs in the sustaining gift that typically results in the status changing to Lapsed. When a sustaining gift fails, your site may be configured to reattempt the transaction a certain number of times between a certain amount of days. If there are multiple reattempts for that sustaining gift, then you will only see the final decline after the Sustaining Gift Status changes to Lapsed.