WP-Cron get delayed

Subject: WP-Cron delayed/stuck while plugin is active — cron lock possibly cached stale

Hi,

I’m seeing WP-Cron get delayed by 30-60+ minutes (sometimes longer) while this plugin is active, and it resolves immediately when I deactivate the plugin.

What I’m observing:

• Checking Tools > Scheduled Actions, all scheduled hooks — not just one — are overdue by the same amount at the same time (e.g. action_scheduler_run_queue, acf_update_site_health_data, and others all showed “53 minutes ago” simultaneously).
• Deactivating Object Cache 4 Everyone immediately unblocks cron — everything overdue fires right away.
• Reactivating the plugin, the delay pattern returns.

Setup:

• Backend: Memcached, 127.0.0.1:11211, plugin version 2.3.3
• Cache hit ratio ~98%, uptime 23+ days at time of testing
• Same plugin is active on our staging environment and does not show this issue, so it may be an interaction with something specific to production (traffic, shared Memcached, or firewall) rather than the plugin alone.

My question:

I think WordPress has an internal “flag” for whether cron is allowed to run. My guess is this plugin might be caching that flag, so it keeps showing the old “not yet” answer for a while even after it’s actually fine to run again.

• Does the plugin cache this cron-related setting?
• Since there are no settings in the plugin, is there a way to exclude just that one thing from caching, without disabling caching completely?

Thanks for your time.