This isn't just an iOS 9.x issue. I have several iCloud accounts that I only use for mail. Mail in iOS 9.1 and OS X 10.11.1 frequently asks for me to re-enter the password for one or more of these "mail only" iCloud accounts. Mail in OS X 10.11.1 then takes the account(s) offline while complaining about the "network". If I just quit and reopen Mail, the account(s) go back online without entering the password(s).
I'm beginning to believe that this is a simple timing glitch. IOW if iCloud doesn't get a response quick enough, it asks for the user to re-enter the iCloud password. This glitch could mainly effect users with slow and/or variable speed internet connections. Which may explain why it happens most often when an iOS device is busy after being rebooted.
BTW you can bet that Apple software developers and testers were/are unlikely to see a timing glitch because they rarely if ever have a "slow pipe"
---GetRealBro
I'm beginning to believe that this is a simple timing glitch. IOW if iCloud doesn't get a response quick enough, it asks for the user to re-enter the iCloud password. This glitch could mainly effect users with slow and/or variable speed internet connections. Which may explain why it happens most often when an iOS device is busy after being rebooted.
BTW you can bet that Apple software developers and testers were/are unlikely to see a timing glitch because they rarely if ever have a "slow pipe"
---GetRealBro