QR code scanning randomly stops working

Starting a year or so ago - not sure with which iOS version - QR code scanning fails >50% of the time. That is to say, I open the camera app and point the phone at a high-quality QR code in good light, and the app doesn't draw a box around the code recognizing that it is there. Invariably, if I force quit the Camera app and restart it, it works fine (100% of the time) in the same conditions. I use this functionality often, so I am getting tired of this time-consuming workaround, especially because it is so reliably repeatable that I am sure it is a bug that could be found and fixed. Indeed, searching the web indicates that this is not an uncommon problem, but the "fix" just consists of my workaround (at best): I find no fixes for the underlying issue.

Anyone with better knowledge or experience on this one?