I got this reply from Leon Stringer: Your website is configured to redirect HTTP connections to HTTPS (secure), but Moodle is configured to use HTTP. Once an HTTPS page is loaded the browser blocks the HTTP content, e.g. CSS and JavaScript.
So you just need to change $CFG->wwwroot in config.php from 'http://yourwebsite' to https://yourwebsite'.
I'm not sure if this is useful for you @Henry, and thanks for the tip @Matt
So you just need to change $CFG->wwwroot in config.php from 'http://yourwebsite' to https://yourwebsite'.
I'm not sure if this is useful for you @Henry, and thanks for the tip @Matt