That exact thing happened to me on my cheap Jamis carbon fiber gravel bike. I hit a rut with my rear tire, hard enough to *maybe* get a flat. The rear tire immediately started rubbing on the frame, and I was like "could I really have broken a spoke on that? I didn't hit it THAT hard?"
No - I'd broken my seat stay.
Jamis was cool about it, at the time they had 2 levels of carbon frames; they replaced my cheapo version with the same frame in the primo construction. It's been going strong for the last three years or so.
Literally, "just riding along"