Thank you for sharing your concern. And please follow the easy troubleshooting steps which might help to solve the issue and please check the QR code scanner is not available in-camera settings, however should definitely be seen on Samsung Internet.
I would suggest checking that it is an option through these steps: launch Samsung Internet > ☰ (in the bottom right corner) > Settings > Customize menu > drag QR code scanner from grey area to the menu.
In case the issue still occurs. Please register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
