Right when iOS 9.0.2 was released, a bug has hit Apple’s iCloud services, specifically Tabs and Keychain services. According to Apple’s iCloud status page:
All iCloud Services – Some users are affected
Users may be experiencing slowness or inability to access iCloud Tabs and iCloud Keychain services.
The outage means users are also being prompted to re-enter their Apple ID credentials again on their device repeatedly. Let us know if you’re being affected by this outage.