What you were expecting to happen, and what actually happened?
I wanted to change my Guild Wars defense team for the next day. It accepted the change, displaying the new team set. However, when the next day started, it always had reset to the one assigned by default. I’ve had this happen to me several days in a row now.
What are the steps to make it happen again?
Go to Guild -> Battle -> Defense, click on the banner of the upcoming team, select any premade team from the pool. The defense tab will update to show the team has been set. Wait a day for the next round of battles to start. The defense team will have reset to the one initially assigned.