I don't see that. Just four lines of header:
Subject:
From
Sent:
To:
Maybe it is picking up stuff, or a setting, from somewhere else?
Ctrl+S does it. But it is a well-hidden feature. I had to ask too.
That might also benefit from a bit of work on the current way of showing things. If you use the Save button on an existing saved search, it offers you a new name. Some software presents a dropdown of existing saved data so that you can choose a new name, or an existing one. That would help people to overwrite saved searches that they no longer want, or simply want to tweak.
Which "flag" is this? Follow Up? That would certainly be nice.