no i never installed a beta. and it is the same build, as indicated in settings/software update. and im just plugging it in as i always do, to itunes in normal pc mode.
for the first time i updated the iphone ios (in this case to 9.2.1.) via itunes, as opposed to via iphone settings/wifi, which is how i always did, previously.
not sure if that can be the issue.
my internet is att wifi and limited, so I wanted to avoid read downloading the software because it would be a waste of a couple of gigs, or whatever it is.