I have tested Ninja Forms v3.13.2 with WordPress v6.9, and the CSS helper classes are working fine as before. Please ensure you have added the helper class in the Field → Display → Container box, as shown in the screenshot below.
If it’s still not working, try reinstalling the Ninja Forms plugin. First, download the latest version from https://downloads.wordpress.org/plugin/ninja-forms.3.13.2.zip. Then, go to WordPress Dashboard → Plugins → Add New Plugin and upload it. When prompted to replace the old version, confirm the action. This process ensures you have the latest copy of the plugin without any corrupted files.
If the issue persists, try temporarily disabling your caching plugin and check again in an incognito/private browser window. Clearing your browser cache is also recommended for best practices.
If it still doesn’t work, please open a support ticket with their support channel, as Mia mentioned above.
Best regards, Faisal Ahammad (Support forum volunteer)
