I love using iMessages on my iMac. But the banner that appears in the upper right hand corner of my screen isn't showing me a preview of the message anymore. Instead, it just says "New Message." I can't figure out how to fix that setting, and I'm getting frustrated with all of my internet searches showing ********s of results for people wanting to increase their iMessage privacy on their phones, when I want to decrease my iMessage privacy on my mac. I'm apparently the only person on earth trying to do this.