(Hi Richard I know this doesn't help answer you question but I just wanted to add that I am having the same problem)
Hi Vitor , I'm running an app on an Samsung Galaxy Note 10. I have left the camera parameter to 'back' but it seems to only use the front camera so its getting my face and not the QR code I am pointing at. I also tried to change the camera parameter to 'front' just in case it worked the opposite way. however that didn't work either.
(I am guessing as there are 3 cameras on the back the code cannot figure out which back camera to use and defaults to the front camera) . I would be helpful it you can help me fix this issue. Thanks.