iOS 16.5 - single sign-in no longer works, or more

Since upgrading to 16.5 ( iPad, iPhone and Apple TV ), it's been impossible to sign into my Xfinity account on all but one device. The process appears to work as usual but, for example, fails to activate the TV app. Or the TV app is activated, but then it loses the setting and one must start over. Deleting and reinstalling the app makes no difference. The problem is with NBC owned apps subscribed through via Xfinity (TNT, ESPN), at least for me.

Never a problem for these many years, until the 16.5 update yesterday.

This means missing NBA playoff games! Not good ...