Settings won't save

[writtenbyk]

When I try to customize my Noptin settings, they won't save. For example:

1. I customize the default success message.
2. I click "Save Settings."
3. I receive a "Settings saved" confirmation, but the default success message reverts back to "Thanks for subscribing to our newsletter"

No matter what setting I try to update, they revert back to factory settings right after I click "Save Settings."

I'm wondering if there's a conflict with my security or caching plugin, perhaps a setting that's blocking the updates from saving that I need to modify or deactivate?

My security plugin is Hide My WP:
https://codecanyon.net/item/hide-my-wp-amazing-security-plugin-for-wordpress/4177158

My caching plugin is LiteSpeed Cache:
https://en-ca.wordpress.org/plugins/litespeed-cache/

Thanks in advance for your help!