Across our app, all of our APIs have degraded at the same time, several hours after any deploys had taken place. In case it's relevant, we're using next@14.2.13
Here is an example from some of them:

As can be clearly seen, around mid-day on the 16th of October, there was a sharp increase in CPU time. Our functions use the Basic CPU, but that setting has not changed for at least months.
Any ideas what could be causing this?
Deployment URL or Custom Domain:Environment (local, preview, production):Project Framework: nextjsBuild Settings: Framework Preset: Build Command (if not default): next build --no-lint Output Directory (if not default): Install Command (if not default):Node/Runtime Version: node v20Package Manager: npmRelevant Packages: