Troubleshoot with Cache Plugins
Sometimes the Cache Plugins are conflicting with WP Statistics. On the below, we are the most common solutions to troubleshoot the issue with Cache Plugins.
Cache plugin option
Make sure the Cache Compatibility option in WP Statistics » Settings » General is enabled. (If it’s already enabled, try to disable it and wait for a while, then check out the Overview page)
Excluding WP Statistics’ REST-API
Ignore the plugin’s REST API namespace for caching. Our namespace is: wp-json/wp-statistics/v2/hit
(You can exclude it from caching or disable REST API caching.)
Note
It is necessary to disable any security plugins that disable the WP-REST API, such as WP-Hide, or add the WP Statistics endpoint to the white list.
Debugging Ajax Response
Sometimes you can debug yourself. Just go to one of the single posts (In private browsing) and enable the Inspect » Network » XHR, then refresh the page and click on the request and see the response.

Cookie nonce is invalid
This means that your site’s Nonce tokens are being cached and reused beyond their designated time frame.
WordPress Nonces can be used for 12 hours before they become invalid. To avoid expired Nonces from being sent to WP Statistics you must ensure pages with WP Statistics are not cached, or not cached for longer than 12 hours.