After last week’s OTA patch, I had the same issue on Zirconia, both with the default app and with OpenCamera. I had been about to file a report, but then another patch came out and the camera focus worked again after I installed it.
(Since patches don’t normally come out so close together, I’d assumed you’d gotten deluged with camera-focus complaints and had released the second patch in response to it. Surprised to hear you hadn’t seen any prior reports.)