iCloud syncing of contacts, calendar not working

outlook until recently was able to sync icloud contacts and calendar. Now gives message error 0X80070057 caldav url is empty. there is a history of this problem in community but no solution from Apple or Microsoft despite promises going back to 2019. they may have fixed it back then since as recently as last month it was working on both my laptop and desktop in Windows 10 but problem is alive and amazingly frustrating.