Why is Mail.app suddenly marking emails as potential spam that were fine before?

I get digests and other things via email (into my GMail account) once or twice a week. On my desktop (M2 Pro Mac Mini, Sonoma 14.7), I have Mail.app (Version 16.0 (3776.700.51.11.1)) setup with the GMail account, and it syncs emails like normal. But in the last week or so, it's started coloring every single mail gold in the Inbox view. A little bit of searching showed that that was Mail marking the message as potential junk, but I don't have junk mail filtering turned on in the settings. I can fix it by moving the messages to Junk and then back to the Inbox, but that sucks. How do I get Mail.app to stop assuming everything is junk?