The iPadOS 18 upgrade has broken QR code reading!!!!
After upgrading to iPadOS version 18, it is not possible to read QR codes with the Camera App on certain iPad models. It also impacts Apps that attempt to read QR codes through APIs. [One partial workaround is to use Code Scan in Control Center, which does work. But that doesn't help Apps that include QR code reading.]
It definitely impacts 7th generation iPads, and seems to partially impact 8th generation iPads. I don't know which other model iPads are impacted.
Apple introduced exactly the same bug in iPadOS 17.4 and fixed it in iPadOS 17.4.1. Apple, PLEASE release an iPadOS 18.X fix for this ASAP. This is a SERIOUS bug.