My iCloud.com calendar has no content
This morning I needed to access my calendar using Firefox on a Windows 10 PC, so I went to iCloud.com.
I found that everything works - I can use Mail, see Photos, iCloud Drive etc - EXCEPT the Calendar. It is completely blank.
As a test I accessed iCloud.com in Safari on my MacBook Pro and the result was the same.
I have Mac mini (2018) and MacBook Pro (2015) both on Mojave; iPad Air 3 and iPhone 7 on iPadOS 15 and iOS 15.
The Calendar on all devices is in sync ( we use a shared calendar) . The Shared calendar is setup on iCloud.com, but it is devoid of data. The date and time on all devices is identical.
How can I fix this.? BTW (not that the bot will listen) I have gone through the Apple support page for this and it is of no help.