This article provides one behavior that SRX App ID junos:MICROSOFT-UPDATE may fail to identify the Microsoft Update HTTPs traffic under Content Delivery Network scenario.
When Microsoft Update application is hosted on a content delivery network (CDN), SRX AppSecure services(AppTrack, AppQoS, APBR and so on)may fail to identify the Microsoft Update HTTPs traffic when using with using App ID junos:MICROSOFT-UPDATE.