I have a site load balanced across two servers using flexible load balancing and for some reason, the slave server is currently not executing the CacheUpdated event on the slave server and is not showing recent changes.

The distributed cache last updated values are the same on both servers but only the master server logs show the cache updated event having been fired. As such, the slave server is currently behind the master.

There are no relevant entries in the log file to suggest an error occurred so I'm not entirely sure what is going on or how this can happen with the lastupdated id being updated but the changes not actually being visible.

Any ideas?

The event handler is wired up as follows:

protected override void ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
{
    CacheRefresherBase<PageCacheRefresher>.CacheUpdated += PageCacheRefresher_CacheUpdated;
}

private static void PageCacheRefresher_CacheUpdated(PageCacheRefresher sender, CacheRefresherEventArgs e)
{
    // Removed check for UmbracoContext - See https://issues.umbraco.org/issue/U4-10150 for reasons why
    NodeHelper.Clear();
    LogHelper.Info<EventHandlers>("Page cache refreshed.");
}

Thanks, Simon

P.S. I should point out that we had a similar issue before but that was resolved