Apple reminders Today smart list doesn't automatically show total today badge count on Mac

I've setup the replacement 'Today' list as a smart list so I can set flagged tasks to be worked on today even though the due date is not today. Smart list has filters set to ANY 'Date today' OR 'Flag Flagged'.

When tasks meet the criteria they DO appear in the actual Today smart list BUT the badge count in the Mac reminders desktop app for the smart list does not update the correct count for the new day once the new day begins. This is the pinned badge count, top left in the Mac desktop app.

However, if I add a new task that meets the criteria for the Today smart list that's also due today, that 'forces' all the missing Today badge counts to appear. Suddenly everything is correct and upto date.

It does show the correct daily badge count in the dock, on the iPhone and on my Apple Watch. This issue only occurs with the Mac desktop reminders app. I'm on the latest versions of everything.

This has the distinct whiff of bug to me. Can anybody shed any light or have a fix?

Thanks