Reminders After Sleep

[mrploppy]

I used to have this problem as far back as Mavericks, but sometime between then and High Sierra it fixed itself (or a system update fixed it). Now that I'm using High Sierra, it's back. I should say first that I'm using a late 2008 MacBook Pro - an unsupported mac for HS, and moreover a Mac that doesn't have power nap. The issue is this:

1. Create a reminder for a particular time, say one hour from now - with Notification Centre alerts on for Reminders.
2. Wait one hour with Mac awake.
3. Reminder alert occurs at the the correct time. Hurrah!
4. On the alert, say Later -> Remind me in one hour i.e. snooze for one hour
5. Allow the Mac to sleep for at least an hour
6. Wake the Mac
7. I don't see an alert for that reminder ever again.

To me this is weird. I would expect, when the Mac wakes from sleep, that it would check if any reminders were due during the time the Mac was asleep and generate alerts for those that were.

Does anyone else see this behaviour? Is it the behaviour you'd expect?

As I said earlier, this used to work as I'd expect sometime between Mavericks and High Sierra but now it's broken again.

 

[mrploppy]

This is driving me nuts because it doesn't fail all the time. It tends to fail more if the snooze time is set to "Remind me in an hour" but I couldn't guarantee that. I've wondered about all sorts of causes e.g. is it the duration of the snooze, does it depend on the method by which the laptop goes to sleep (idle sleep versus explicitly commanding sleep), is it caused by Do Not Disturb, but I can't definitively say what conditions cause it fail.

No-one else suffering this?