At times It so happen when your required plugin or theme is not working as expected or described by the plugin or theme author. Most often it happens due to WordPress theme or plugin conflicts. Other possible reasons are an outdated plugin, theme or WordPress version. I suggest you few debugging techniques to rule out any WordPress theme or plugin conflicts.
Check WordPress version
Make sure you are using latest WordPress version. Try reinstalling latest version from Dashboard/Updates section in your WordPress admin panel
Rule out plugin related conflicts.
Deactivate all plugins except the one you are testing. Now perform the required actions on the website & check the results, if successful then try to find out conflicting plugin by reactivating all plugins one by one. Generally It will not effect data of deactivated plugins & will b available again on reactivation.
Rule out theme related conflicts.
If above technique do not work then switch your theme to default WordPress theme to check theme related conflict & issues.
At times WordPress theme or plugin conflicts create panic but I hope one of the above solution will help you to figure out the problem. Leave a comment to let us know if this article was helpful for you.