The only time I have had a problem with changing the Application Title in Startup is when I wasn't the owner of the DB. But I am the owner of the DB and I cannot permanently change the title. I can change the title in Startup but if I close and reopen the DB then the old AT is still there. I am a member of the Admin group. I am the owner of the DB object.
When I try to change any permission on the Current Database in the Security dropdown section as either myself or as a member of the group Admins I am told that to change permissions for this object I must have administer permissions for it. Why don't I if I am a member of the Admins group? I can change permissions everywhere else.