Just noticed there is a new build for iOS 9.3 but it's still named as
iOS 9.3 beta
... so this is not Beta 2 presumably.
This build is 13E5181f and was released on 14 Jan.
The previous build was 13E5181d and I think released on 11 Jan.
I wonder what changed. Perhaps worth gettings this for anyone having problems with the previous upgrade.