All sorts of weird things happen over maintenance. Your march may have landed before or after maintenance, but the entire round trip definitely crossed maintenance time at some point. The reason one march might get XP and the other does not is simply because it's a bug. No XP is definitely the most common maintenance bug, but it doesn't happen every time. There are plenty of other potential bugs, but none of them happen 100% of the time.
Quote Originally Posted by tindris View Post
maintenance is cursed
^^ This.