Response declares no caching policy

What this means

Neither Cache-Control nor Expires is present on this response, so browsers and intermediary caches are left to guess. Heuristic caching is inconsistent across clients, which means repeat visitors may re-download the page every time and CDNs cannot reason about freshness.

How to fix it

Send an explicit Cache-Control on every response. Even a deliberate Cache-Control: no-store for personalised pages is better than silence; static assets should carry a long max-age with immutable.

Fix effort

This check needs a developer fix: it turns on a routing, hosting or infrastructure decision that no automatic edit can make safely.

Authoritative source

https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Caching