For those still wondering about why they were "not allowed" to scan the other QR code: I suspect this is related to potential abuse vectors via QR codes (yes, we know, requiring the hacker to spoof it via a fake app instead of an ebook is not the answer).
Watch https://www.youtube.com/watch?v=cIcbAMO6sxo or read https://www.revk.uk/2020/01/eicar-test-qr.html for some background.
~f