If I understand your issue correctly, you’re having a “Mixed Content” error, and it happens when a site that’s supposed to be served over HTTPS (secure) is also serving some of its content over HTTP (non-secure). In your case, it appears that your CSS and JavaScript files are being served over HTTP, which is causing the problem.
First, ensure that your website’s URL in the WordPress settings is using HTTPS. You can do this by going to “Settings” > “General” in the WordPress admin area. Both the “WordPress Address (URL)” and “Site Address (URL)” should start with https://.
If that’s already correct, or if changing it doesn’t fix the issue, you’ll need to replace all the HTTP URLs in your database with HTTPS (if you haven’t tried it yet). Note that this should be done carefully, as making mistakes in your database can break your site. So to do that, you’ll need to use a plugin like Better Search Replace
Here’s some step-by-step that you can follow as a guide:
- Install and activate the Better Search Replace plugin.
- Go to “Tools” > “Better Search Replace” in your WordPress admin area.
- In the “Search for” field, enter your site’s URL with
http://(e.g., http://yourdomain.com). - In the “Replace with” field, enter your site’s URL with
https://(e.g., https://yourdomain.com). - Select all the tables.
- Run a test first to make sure everything is working correctly. To do this, check the “Run as dry run?” option. If it is, uncheck the “Run as dry run?” option and run the replacement.
Remember to deactivate and delete the Better Search Replace plugin when you’re done using it.
And if you’re using a caching plugin, don’t forget to clear your site’s cache and your browser’s cache to make sure you’re seeing the latest changes of your site.
If you are not comfortable with changing database values using the Better Search Replace plugin, you can also try using the Really Simple SSL plugin to force your WordPress installation to use HTTPS on all of its pages and resources.