Persistent cache critical issue in WordPress

I recently discovered an issue affecting all the sites of my UK-wide lead generation network.

The Site Health Status showed a Persistent cache critical issue, and it seemed to be caused by an issue with the cache. I could not tell if it was my existing cache plugin, or something else.

There was also often a second issue appearing, not critical but more of a recommended action needed when a scheduled event had failed to start. More likely an issue with Cron jobs.

I researched all I could about a Plugin that could fix the persistent cache issue and found Docket Cache, a plugin that seemed not only to help with persistent cache issues but also with Cron jobs issues.

When you install Docket Cache, you need to connect the Cronbot first by clicking the Connect button on the Cronbot tab. After that, click the Overview tab, and Flush the cache.

Once the Persistent Cache is flushed. No critical issue will appear any longer.