The iPadOS 17.4.1 update that Apple released this morning addresses a bug that could prevent certain iPads from being able to scan QR codes.
According to an Apple Support document, a bug in iOS 17.4 impacted the camera on the 6th-generation iPad, 7th-generation iPad, 10.5-inch iPad Pro, and second-generation 12.9-inch iPad Pro, preventing camera apps from being able to scan QR codes. Apple says that customers affected by this issue should update to iPadOS 17.4.1 to fix the problem.
Prior to iPadOS 17.4.1, Apple was suggesting that iPad users unable to scan QR codes with the Camera app and other third-party apps use the Code Scanner function in the Control Center.
Apple's release notes did not mention the bug fix, perhaps due to the limited number of iPad models that are impacted. iPadOS 17.4.1 also added other unspecified bug fixes and security improvements.
Source: Macruomrs