Custom Registration form & Custom CSS files not loading

Recently we updated WP Members to latest version 4.0.3 and now the custom Registration template and CSS are not loading.

The Registration form is named: register-form.php
The Custom CSS file is named: wp-members.css
Both files are in my theme folder. And previously this worked fine.

I have tried both of these shortcodes:
[wp-members page=”register”]
[wpmem_form register]

Any idea why this suddenly loads only the default registration form, without the custom CSS file I created

https://ww.wp.xz.cn/plugins/wp-members/