Inside of one of your `app/` pages, the page was initially generated statically at build time and then during runtime either a fallback path or path being revalidated attempted to leverage dynamic server values e.g. `cookies()` or `headers()`.
Prevent usage of these dynamic server values conditionally which can cause the static/dynamic mode of the page to differ between build time and runtime.
Leverage `export const dynamic = 'force-static'` to ensure the page is handled statically regardless of the usage of dynamic server values. Alternatively, if you prefer your page to always be dynamic you can set `export const dynamic = 'force-dynamic'` and it won't attempt to have the page be statically generated.