From the error code (HTTP 403 Forbidden) and the source code of your website my guess is that this is being caused by WP Super Cache. Please see Is WordPress Popular Posts compatible with page caching plugins? for suggestions / recommendations.
If you have any further questions don’t hesitate to ask, ok?
>If you have any further questions don’t hesitate to ask, ok?
Yes, I use SuperCache and noticed that the most popular pages visit reduced some time ago. Potentially SuperCache was updated.
Currently I’ve cleared the cache and the problem gone. Will set up removing of old cache at the plugin. Plus I’m going to move to Lite Speed cache due to the Lite Speed server.
The Lite Speed cache plugin has two more or less relevant settings to the case:
“Default Public Cache TTL” that will be reduced to 12 hours and “Default REST TTL”. And I’m not sure about the second one. Should I reduce it?
No, I don’t think changing the latter is necessary. Leave it as is and if you encounter any further issues please let me know and I’ll have another look.
Already moved to LSCWP. Set the pages TTL to 6 hours. Think that this will be anough.