I switched themes, and have now figured it out. Thank you for your willingness to help me!
Thanks, Steve, for your input. However, I contacted JetPack support before I came here. This was their response:
All I see is information about WordPress’ wp_schedule feature, relating to scheduling cron jobs – Jetpack does not have the wp_schedule inside its actual code. Here’s more information on wp_schedule:
https://codex.ww.wp.xz.cn/Function_Reference/wp_schedule_event
Based on what they sent, I’m not sure how it pertains to Jetpack.
Further advice, anyone?
