Hey Dcousins,
Thanks for contacting us about this. I will be happy to assist with this.
Sorry to hear about this issue.
We have had no other reports of this recently, so with that in mind, I am thinking there could be a software conflict with your site and Optin Cat – for example, something caching the page or a recent update.
Have you recently updated any plugins or WordPress itself ?
To search for conflicts, please follow these steps.
1. First, please deactivate all plugins except Optin Cat and see if the issue persists.
2. If the issue is resolved, reactivate your plugins one by one, testing after each to see if the issue returns.
3. If no conflict is found among your plugins, try reverting to a default WP theme like ‘Twenty Twenty’ and see if the issue is resolved.
Head here for detailed instructions:
https://fatcatapps.com/knowledge-base/search-for-conflicts/
If you find a conflict with a plugin or theme, please let us know.
Let us know how it goes and if you have any success with this.
All the best and have a good day.