I think I was able to troubleshoot the issue with phone calls not coming in (at least for me).
There is something broken (after the update) with the "pop-up" notification for incoming calls. For those that don't know what that is, it's a little pop-up window that comes up (rather than the entire screen) for one to answer the phone, when you're in the middle of doing something on your phone. I absolutely loved this setting, until now. When I turn that off, phonecalls come in without any issues, when the phone is on standby. When I enable it, that's when calls will be ringing, but they don't actually get sent through to the phone. It's so odd. I'm not sure I'm gonna go in to have this checked out, but...if someone else can try that out, to make sure that it's not isolated to my phone, I'd really appreciate it.
To enable/disable that option, go into the phone dialer. Menu>CallSettings>IncomingCallNotifications>Toggle box for "Show notification pop-ups for incoming voice calls when the screen is on".
In order to test, enable that first, put the phone on standby, and call the phone. The phone should wake up. After you've made that first attempt, go back to the call settings and turn the setting off. Then, put the phone on standby and call it again.
I'm leaving it off for now, as this is a deal breaker for me, if it's not getting my calls through to my phone.