While testing the EWS and ActiveSync functionality, I often notice a considerable delay between the web/ActiveSync clients and a EWS Connected client (Outlook for Mac v16.25).

While the sync speed between an ActiveSync client and the server is mostly good, there seems to be a problem syncing newly created Category tags from the mobile device to the server (and EWS of course). The mobile device keeps thinking that the Category exists, but it can not be found on another device / web. Even added to an existing event that already contains a Category (created on a EWS client and visible in the web ui), the phone displays 2 categories while the other interfaces only list one.