iCloud for Windows Outlook Add-In no longer works

I have successfully combined iCloud (apple household apart from PC) for Windows and Outlook 365 for a long time. My primary requirement is the calendar integration with Outlook as I have numerous calendars that I need to see in one place.

Recently the add-in stopped working. When I install iCfW the add-in for Outlook installs and shows in Outlook add-ins as enabled however it no longer appears in the taskbar and the Calendars do not show in the Calendars tab.

I have uninstalled and reinstalled everything over and over with no success. Does anyone have this problem?

Is this a Windows or Apple update that has broken it and if so is anyone fixing it?

(and before anyone asks, yes I do need to use it this way, I have tried every internet fix I can find and I have turned it off and on again :)