Hosting, Proxy and Application Configuration
Compare public secure basic URLs with fixed addresses in CMS blocks and theme resources. A correct HTTPS certificate does not correct old HTTP references.
Response headers can be created in the web server, reverse proxy or in Commerce extensions. Check the publicly visible combination, especially if Varnish or a CDN is upstream.
Where to check the setting in Magento
Check the headers of the final HTTPS response and the jurisdiction of the application, web server, and CDN. In the case of CSP rules, additional checkout and payment integrations must be tested. A general blocking rule from another shop is not a secure standard correction.
Example of this specific finding
Illustrative control case: An HTTPS page integrates a script via http://. Browsers can block this insecure resource; a form may not work then.
follow-up audit in Magento
Check Storefront, Account and Checkout separately. A public catalogue page rule must not inadvertently release personal responses or block necessary payment functions.
Switch the responsible integration to an actually functioning HTTPS resource and re-check the browser console and the affected function.
Derogations and scope
Simply replacing the http string with https does not help if the target does not offer a valid HTTPS.
Reference: Magento Open Source or Adobe Commerce with classic storefront. Consider store views and extensions; other storefront architectures have their own configurations.
Classify the general error
Definition, system-independent causes and further correction examples: Track the causal involvement to the source