It could be that the app is not optimized for Google Pixel 4a phones, or there could be some other issue causing the QR code scanning problem. It's good to know that the issue doesn't seem to be limited to just the Pixel 4a since it has worked on other Android phones. As for alternative methods, you might want to try entering the server information manually into the app, if that's an option. That way, you can bypass the need for the QR code altogether. You can also use the Smart Engines app for QR scanning and OCR in general. You can use it for any future document scanning needs!
It could be that the app is not optimized for Google Pixel 4a phones, or there could be some other issue causing the QR code scanning problem. It's good to know that the issue doesn't seem to be limited to just the Pixel 4a since it has worked on other Android phones. As for alternative methods, you might want to try entering the server information manually into the app, if that's an option. That way, you can bypass the need for the QR code altogether. You can also use the Smart Engines app for QR scanning and OCR in general. You can use it for any future document scanning needs!