Since the lollipop update, my S4 will randomly stop accepting calls and send then directly to voicemail. No indication of missed calls, just an occasional notification of voicemail message when someone leaves a message. It seems to happen more often when wifi is active, but happens even when it is not. I've looked over similar questions here and have tried the cache flush trick and the *73 end call forwarding trick and checked that auto-forwarding is off. Nothing seems to help.
I'm also getting the ringer volume selfchange to super-quiet and intermittent power-off problems also reported here. Running baseband version I545VRUGOC1 Android version 5.0.1 Kernel version 3.4.0 build #LRX22C
So when is the fix due to be pushed out? I saw a week ago it was "in the next couple of days".