There are a number of issues happening with the Internal WP-cron system that is used by WordPress. In order to fully determine where this problem lies, we will be doing extensive testing on this site over the next few days.
There are many plugins that have known potential issues when it comes to interactions with wp-cron, such as W3 Total Cache’s database or object caching functions, however this is not the only site that has these features implemented and has not been determined to be the present problem.
As this is may be related to specific or combinations of plugins we expect to have to disable and re-enable plugins during the testing phase. Most of these plugins may only present as inactive sections or functions of the website and as such should not greatly interfere with user experience.
We expect to be able to trouble shoot this with a minimum of site downtime and should not greatly impact access until such time as we have narrowed down the problem. We will post an update once this is fixed.
Thank you for your continued support and visits.