The common WordPress-specific issues.
SITE ADDRESS MISMATCH
Settings > General must show https for both WordPress Address and Site Address. If they show http while a redirect forces https, the two fight permanently.
If those fields are greyed out, they are set in wp-config.php. Edit them there.
LOCKED OUT AFTER CHANGING THEM
Add to wp-config.php above the stop editing line:
define('WP_HOME','https://yourdomain.com');
define('WP_SITEURL','https://yourdomain.com');That overrides the database and restores access.
MIXED CONTENT
Run Better Search Replace across all tables, from http://yourdomain.com to the https form. Back up first.
REDIRECT LOOPS
Usually three redirect mechanisms at once: cPanel Force HTTPS, an .htaccess rule, and a plugin's SSL setting. Keep one.
If behind a load balancer or proxy, WordPress may not detect https correctly. Adding an appropriate check for the forwarded protocol in wp-config.php resolves it.
ADMIN OVER HTTP
Force it with define('FORCE_SSL_ADMIN', true); in wp-config.php.
AFTER ANY CHANGE
Re-save permalinks and clear every cache.
