iOS Swift, AVCaptureMetadataOutput rectOfInterest for linear barcodes

Does setting rectOfInterest for scanning linear barcodes makes sense? I'm trying this in my app, and so far it's working almost as expected, however there're some cases that when I'm scanning the barcode, it gets scanned even if the barcode is not fully inside the rectOfInterest, lets say its 20-30% inside vertically. Is this expected to happen?