I noticed that the scanner works just fine on my Samsung phone if I open the camera app first, select macro and go right to the StoryGraph's barcode scanner. So far, it picks the correct book most of the time. Sometimes it scans too fast and misses. I have to switch to the macro mode in my camera app for every single book though, so that's not really a great option. It seems that without it, the scanner just can't focus. Everything keeps looking blurred.
Just thought you might find that useful.

Android version: 13
Samsung One UI version: 5.1

I would also love it if the bar code scanner wouldn't request access to the camera every time I use it!

Spending some time in the next couple of months to improve the barcode scanner!