My S22 ultra won't scan a QR Code from the camera app (it always did before) and the QR toggle in the camera settings is set to on. I did find however that you can scan a QR code by dragging down twice from the top to see features settings and (for me anyway) sliding over one screen to the right "Scan QR Code" is right there. I tapped on that, and it worked great. I would like it however if the camera app worked like it used to.
