Outlook calendar issue

I have calendar set up on iCloud so that it is accessible via PC Outlook calendar/iPad/Iphone.  this pretty much works except that when I create a new  calendar item on the PC Outlook calendar then for some reason I am unable to edit it or delete it from the PC. I can only do it from the iPhone or iPad. I have no idea what to look for to correct this. Any suggestions would be most appreciated. Thank you.