Not saying this will resolve everything but it should help
In Outlook click
File
Options
Add-ins
Click on iCloud Outlook Add-in
look towards bottom left for Manage
Click on COM Add-ins and select Disables Items and click go
Select Addin Icloud Outlook Add-in and click on Enable
You will need to close Oulook and WAIT about 30 seconds.
Restart outlook and the refresh button is back
Good luck
