WordPress sites behind a plugin-managed certificate (Really Simple SSL, host auto-SSL) often serve the leaf certificate only after a migration, dropping the intermediate that proves the CA.
WordPress sites behind a plugin-managed certificate (Really Simple SSL, host auto-SSL) often serve the leaf certificate only after a migration, dropping the intermediate that proves the CA.
Re-issue the certificate from your host's control panel so the full chain is installed, then clear any caching plugin and CDN cache. Run the SSL check below — it reports the chain exactly as browsers see it.
WordPress has its own failure mode, but ERR_CERT_AUTHORITY_INVALID has a wider set of causes. The most common one overall is: The server serves only the leaf certificate and omits the intermediate bundle.
Concatenate the intermediate certificates after the leaf in the certificate file (fullchain, not cert) and reload the server. Desktop Chrome sometimes hides this via caching, so always confirm with an external check.
An external SSL check builds the chain from scratch with no local trust store shortcuts, so it shows a missing intermediate that your own browser may be silently caching around.
WordPress sites behind a plugin-managed certificate (Really Simple SSL, host auto-SSL) often serve the leaf certificate only after a migration, dropping the intermediate that proves the CA.
Re-issue the certificate from your host's control panel so the full chain is installed, then clear any caching plugin and CDN cache. Run the SSL check below — it reports the chain exactly as browsers see it.
The browser could not build a trust path from the certificate the server sent to a root it trusts. Usually the server is serving only the leaf certificate without its intermediates, or the certificate is self-signed.