scheduled Reminders do not appear on iMac
High Sierra 10.13.6
iMac
Reminders 5.0 (1457.4.1)
First, just to avoid misunderstandings: my Reminders are NOT synched to any other device. They live on my iMac and nowhere else. They are NOT in iCloud or any other internet place.
Every day I open Reminders and hit Command-T to show Today's Reminders. I have about a dozen Reminder lists. Recently Reminders from only one list have been appearing. The others are still there in their respective lists but it's as though only one list is being accessed when I want to view Today's Reminders. I can find no menu command that would regulate that.
Any ideas or advice to get back to status quo would be most welcome.
iMac, OS X 10.11