We have just made an update based on your question. You have probably set Athletics.app to automatically manage the reserve list for the category and event for which you are trying to change the registration status. As soon as the registration status is then 'Verified', 'Accepted' or 'Reserve', Athletics.app automatically determines the registration status.
The update ensures that you now get a clearer indication that this is done automatically when you want to change the registration status.
This has been automatically translated into English