no_headlineCAP <headline> is empty โ that's a problem because many alert displays use it as the message's primary label.
CAP ยง3.2.2 makes <headline> optional but recommends it: many downstream renderers โ this report included โ use it as the message's primary label. Without one, a reader (or a report like this) has to fall back to WEA text, <event>, or the message's alert-level <references> just to say what the message is about.