Outlook calendar tab slow to respond when iCloud calenders being used

In a nutshell: When iCloud calenders are integrated in MS Outlook on a PC, opening the calendar tab takes very long.

Dear Community,

I have the an issue similar to the one davekenny78 posted here a year ago. His conversation is closed without solving the issue, therefore I am opening a new conversation, hoping for a development or new ideas.

1. After installing iCloud for Windows, Outlook automatically disabled the iCloud AddIn because it detected that it causes Outlook to start slowly.

Following this instruction, I could enable it manually. After a restart, Outlook informed me that the iCloud AddIn slowed Outlook down and asked me if I wanted it to be disabled. I said No.

From now on, my iCloud calenders were available to me in Outlook.

2. Unfortunately, the warning was true. Not only does Outlook start up slower. Each time I switch from my emails or any other tab to the calendar tab, it takes a long time to open (up to 30 seconds). Once I wait for the 10-30 seconds the calendar runs fine. As I move to mail in Outlook and then back to calendar often, I encounter the delay dozens of times each day.

3. Restarting my laptop did not help. Windows updates are all installed. Uninstalling iCloud for Windows, restarting the computer and reinstalling iCloud for Windows did not solve the issue, either.

Can someone help me and others with the same problem resolve this long delay?

Many thanks!

Jo