I don't know whether it's normal but I know online check-in on QR is such a stupid system (especially given how much they promote it), I've had it happen many times that I check-in online only to have them print me a new boarding pass at the gate so they can give me a hang luggage tag and a boarding pass in the wallet.

Admittedly this was at the old DOH, but I haven't seen many pax with printed out BPs..