We suggest you to do the following toubleshooting steps:
1. Clear plugin’s cache content.
2. Clear any server cache’s content.
3. Check if the plugin’s settings page is loading.
4. Also, please check for any plugin conflict or theme conflict. To do this, disable all the plugins at once and enable them one by one to find out out the conflicting one. If this does not help, please try to switch the website’s theme to another one.
Do let me know whether these troubleshooting steps help or not.