Calendar and Reminders not restored from iCloud Data Recovery

This afternoon, I inadvertently deleted a Reminders List. I therefore turned to Data Recovery in my iCloud account on iCloud.com to recover.

iCloud.com > Data Recovery > Restore Calendars [which restores calendars and reminders]

Listed were 10 archives:

Today 0:59

Yesterday 0:59

22 Jul 2024 0:59

20 Jul 2024 0:59

19 Jul 2024 0:59

18 Jul 2024 0:59

...

I selected Today 0:59. Shortly after, a message popped up stating Calendars and Reminders had been restored. I then received an email confirming such. Furthermore, a new backup had been created Today 14:07 - this is the backup of Calendars and Reminders before the restore back to Today 0:59.

However, Calendars and Reminders HAD NOT been restored from Today at 0:59. I therefore tried Yesterday 0:59 the same result - NO RESTORE and new backup file created prior restore - Today 14:24.

I can confirm that absolutely nothing changed in both Calendars and Reminders after each restore. In Calendar, appointments that had been deleted this morning - and therefore not in Today 0:59 or Yesterday 0:59 restores - were not restored to Calendars. Reminders that had been added this morning - and therefore not in Today 0:59 or Yesterday 0:59 restores - remained.

Both restores did not restore to date/time of chosen restore on iCloud, MacBook, iPhone. For both restores, Calendars and Reminders remained as before restore.

It seems that:

• • Despite confirmation that the restore completed - the restore simply did not work/happen.
  • Or, before starting a restore, the system automatically performs a new back up of existing data, and that the system used this new back up [which would now be the latest backup] to restore from rather than the chosen previous restore.

Unfortunately, Calendars and Reminders that are synced with iCloud are not included in a Time Machine backup. Therefore, the only backups of these items are those on iCloud - which is not working.

• macOS up to date - Sonoma 14.5
• iPhone iOS up to date - 17.5.1
• iCloud account - same iCloud account signed in to iCloud.com, MacBook, iPhone (I only have the one iCloud account)

I spoke to a Senior Advisor at Apple Support. He confirmed that I was doing everything correct and that each of my restores should have reverted my Calendars and Reminders back to the date/time of the chosen restore. He has now escalated to Apple Engineering.

In the meantime, I was wondering if anyone else has experienced similar and if so, did they resolve and how?