Older Android versions ship an outdated root store and fail on chains that modern desktop browsers accept.
Older Android versions ship an outdated root store and fail on chains that modern desktop browsers accept.
Reissue the certificate with a chain that terminates at a root present in older Android trust stores, and confirm the server sends every intermediate. Updating the device is the only other fix.
Android 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.
Older Android versions ship an outdated root store and fail on chains that modern desktop browsers accept.
Reissue the certificate with a chain that terminates at a root present in older Android trust stores, and confirm the server sends every intermediate. Updating the device is the only other fix.
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.