Billing Usage Notification (Storage R2) did not fired

I set up a test notification as per attached to fire after 10 writes (incorrectly named read!), when I set this it was at 9, but over the last day it has gone to 10. The notification did not fire. Note that when I “test” it via the test button it fires.

Any idea what is going on?

For how long has the threshold exceeded the limit value? I believe usage notifications are fired once or twice per day.

It has exceeded it for about 6 hours within the same day now.