Verify that you are enabling that setting directly on the kiosk computer itself (not from the admin area on another computer).
Verify that you are using the same browser for the kiosk screen and for updating the setting.
If you are using windows, make sure you are logged into windows with the same user id when making the setting and then when testing it (sometimes system admins use super ids when making settings)
The last step would be to go to the setting and click on Save Changes one more time even if the checkbox is already checked. Clicking on Save Changes will ensure that the cookie is set properly.
The camera on most fairly modern android phones should automatically read a QR code. This feature has been built in since Android 8.
The Android phones do need to have Google Lens activated. It usually is by default, but if not open the camera, click on the Setting gear and look down the list for the Google Lens switch.
Android 7 and below will require an app to read barcodes. Here's a good article that explains all this for android and even has link to some apps.
Up to date IPhones should read the codes automatically by simply using the camera. If not, you can find plenty of QR code scanning apps in the App Store.
Some of the newer scanners come from the factory programmed for QR codes only. This is usually solved by simply scanning a code in their user manual to add barcode scanning to its skills. Don't hesitate to give us a call to assist you with this.