CSS and JS files of s2Member are not loaded on your page, that's why your form does not work well!
To solve this problem, you have to know the cause, here are some suggestions:
- If you are using an external Wordpress PHP file with "do_shortcode ()", add
<!-- s2member --> as an HTML annotation in "text" section of your Wordpress page or article so that s2Member loads these files.
- Disable your security and cache plugins (JS and CSS minification and compression, etc ...) and try again.
- If there is still no better, disable all plugins except s2Member and retry your form and then reactivate one by one to find the one that has a compatibility problem.
Best regards, Brice.